Plumbing interview questions

Your team wants to start doing sewer line replacements with excavation. It needs new equipment and brings new safety risks. How do you decide?

Situational · Adding a service line

Strong answer

Looks at demand and margin, equipment and training cost, trench safety and insurance, permits, who would run it, and tests it on a small scale before committing.

Red flags

Says yes because competitors do it, or no without looking at the numbers.

Average ticket jumped after a new technician commission plan, and so did complaints about upselling. What do you do?

Situational · Pay plans and honest selling

Strong answer

Reviews the jobs and complaints, separates honest options from pressure, changes the pay plan so it doesn't reward overselling, and resets standards with the team.

Red flags

Keeps the plan because revenue is up, or scraps commissions without understanding what happened.

The master plumber whose license your company works under gives notice. What do you do?

Situational · Protecting the company license

Strong answer

Checks what the state requires for the qualifying license, starts finding or developing a replacement right away, reviews open permits, and makes sure the company never works without a qualifier.

Red flags

Assumes it can be sorted out later.

Walk me through how you'd judge whether a residential plumbing company is healthy from its monthly numbers.

Technical · Reading the business

Strong answer

Looks at revenue per technician, margin by job type (drains, water heaters, repairs, sewer), average ticket, conversion, callbacks, turnover, receivables and cash, and says what each would trigger.

Red flags

Looks only at revenue or the bank balance.

Tell me about a decision your plumbers pushed back on, such as a change to on-call, commission or take-home truck rules.

Behavioral · Making unpopular decisions

Strong answer

Explains the business reason, told the team directly, listened and adjusted what had merit, held firm on the rest, and can show the result, such as turnover or callbacks.

Red flags

Forced it through with no explanation, backed down at the first complaint, or measured nothing afterward.

Tell me about something you did that got plumbers to do things right when no one is checking, like pulling permits on water heater swaps.

Behavioral · Shaping field behavior

Strong answer

Names a specific practice, such as backing a plumber who refused unsafe trench work or rewarding honest callbacks, and how they knew it took hold, like permit counts or inspection results.

Red flags

Talks only about posters, slogans or handbooks.

New water heater installs are getting callbacks for leaks and pilot problems. Where do you start?

Situational · Fixing repeat failures

Strong answer

Pulls the callbacks by installer, model and failure, inspects a few jobs, checks training, parts and the install checklist, and fixes the causes.

Red flags

Tells installers to be more careful.

After-hours emergency calls are growing, and the on-call plumbers are burning out. What do you change?

Situational · Sustainable after-hours coverage

Strong answer

Looks at which night calls truly need a visit, adds phone triage, spreads the rotation fairly with a backup, sets fair on-call pay, and weighs adding a dedicated night plumber.

Red flags

Tells the team on-call is part of the job, or stops answering after hours without a plan.

You find a plumber working in a sewer trench deeper than their head with no shoring or trench box. What do you do?

Situational · Excavation safety

Strong answer

Gets them out immediately, has a protective system put in and inspected by a competent person, and reviews how the job was planned and why the crew went in.

Red flags

Tells them to finish quickly and be careful.

Walk me through how you'd standardize the way technicians present repair options in customers' homes.

Technical · Standardizing in-home process

Strong answer

Sets a clear sequence (diagnose, explain, present priced options from the price book, let the customer choose), trains with role-play, and checks it with ride-alongs and customer feedback.

Red flags

Hands out a script and expects technicians to follow it.

Tell me about a manager under you who kept missing a standard, like water heater permits not pulled or drain callbacks staying high.

Behavioral · Holding managers accountable

Strong answer

Showed the gap with data, found whether it was skill, staffing or process, set a dated plan, followed up, and replaced or reassigned the manager when it didn't change.

Red flags

Kept giving reminders with no consequence, or did the manager's job for them.

Tell me about a change plumbers resisted at first, such as tablets for invoicing, GPS tracking or truck stock rules.

Behavioral · Leading change

Strong answer

Explains how they involved the field early, handled real complaints, measured adoption, and what the result was.

Red flags

Announced it and blamed people who didn't follow it.

Walk me through how you'd check whether the flat-rate price book is priced right.

Technical · Checking the price book

Strong answer

Compares each task's price to actual labor time from job data, parts cost, the true cost of a truck hour and target margin, and updates the outliers first.

Red flags

Raises everything by the same amount each year.

Operations wants a new sewer camera and a hydro-jetter this year. How do you evaluate it?

Situational · Equipment investment

Strong answer

Models the added jobs and revenue, how often each will be used, financing versus cash, maintenance and payback, and sets measures to check after purchase.

Red flags

Approves it because the team wants it, or rejects it as too expensive without a model.

Receivables are growing because more customers are on in-house payment plans for sewer replacements. What do you do?

Situational · Payment plan risk

Strong answer

Reviews the terms and who approves them, checks state lending rules, compares them with third-party financing, tightens approval rules, and tracks the aging every week.

Red flags

Keeps offering plans because they help close sales.

Your insurance premium jumps after two water damage claims caused by your own work. What do you do?

Situational · Insurance and claims cost

Strong answer

Reviews the claims and causes with operations, supports quality fixes, looks at deductibles and coverage, and shops the policy with clean information.

Red flags

Just pays the increase, or switches carriers without fixing the cause.

Tell me about a time your cash forecast was badly wrong, such as a mild winter with few freeze calls.

Behavioral · Forecasting seasonal swings

Strong answer

Explains what they missed, how quickly they told leadership, what they did about cash, and how they now build weather and seasonality into the forecast.

Red flags

Blames the weather and changed nothing in how they forecast.

Tell me about a system you put in place to get field payments and tickets into the books faster, such as for after-hours leak and drain calls.

Behavioral · Improving finance systems

Strong answer

Names the problem (late deposits, missing tickets), the system (mobile payments, daily technician close-out), how they got technicians to use it, and the result.

Red flags

Describes a system someone else implemented.

Walk me through how you'd raise revenue per plumber when most calls are small drain and fixture jobs.

Technical · Revenue per plumber

Strong answer

Checks conversion, drive time and first-visit completion, stocks trucks to finish jobs, makes sure plumbers offer camera inspections on repeat drain calls and maintenance plans, and coaches each one's weakest step without pushing work the home doesn't need.

Red flags

Tells plumbers to sell more, or raises prices without looking at where the day goes.

Gross margin on water heater installs dropped last quarter. What do you do?

Situational · Margin decline

Strong answer

Checks equipment and parts cost against the price book, labor hours, permit and haul-away costs, callbacks and discounts by plumber, and fixes the biggest causes first.

Red flags

Raises all prices without knowing why margin fell.

A customer says your plumber's work flooded their finished basement and wants you to pay for everything. What do you do?

Situational · Damage claims

Strong answer

Gets the facts quickly, documents the scene, involves the insurer when appropriate, treats the customer fairly and fast, and fixes whatever caused it.

Red flags

Denies it outright, or pays everything without looking.

You have budget for one experienced plumber or two apprentices. How do you decide?

Situational · Hiring tradeoffs

Strong answer

Weighs current demand, licensed supervision rules, who would train the apprentices, and the cost and payoff of each over time.

Red flags

Picks the cheaper option without considering supervision or training.

Tell me about a time you let go of a long-time plumber, such as one who kept skipping permits or pressure tests.

Behavioral · Letting someone go

Strong answer

Explains the documented problem and fair warnings, how they handled the meeting with respect, and how they talked with the team.

Red flags

Avoided it for years, or did it without documentation.

Tell me about a struggling plumbing service team you took over, such as one with high drain callbacks or plumbers leaving. What did you change first?

Behavioral · Turning around a team

Strong answer

Diagnosed the causes with data and ride-alongs, changed specific people or processes first, set measures like callbacks and average ticket, and shows the result.

Red flags

Is vague, or claims success with nothing to show for it.

Walk me through how you check a bathroom remodel's drain, vent and supply rough-in before the inspector comes.

Technical · Rough-in inspection readiness

Strong answer

Drain slope and fittings, vent connections and trap arms, cleanouts, nail plates where pipes pass through framing, pipe supports, capped supply lines, and the system holding its test.

Red flags

Looks it over quickly and lets the inspector find problems.

Three days after a repipe, a homeowner calls about water stains on the ceiling. What do you do?

Situational · Leaks after a repipe

Strong answer

Gets out there fast with the plumber, finds and fixes the leaking joint, arranges drying and repairs, and checks the crew's methods, such as fitting checks and pressure tests.

Red flags

Sends someone to patch it and doesn't look for the cause.

You find a plumber working alone in a crawlspace with standing sewage, no gloves and no respirator. What do you do?

Situational · Sewage exposure safety

Strong answer

Stops the work, gets proper protective gear and ventilation, checks whether the space needs confined space procedures, decides whether entry is safe, and talks with the crew about sewage hazards.

Red flags

Lets them finish since they're almost done.

A homeowner is upset about drywall dust everywhere and a scratched floor after your crew's job. What do you do?

Situational · Protecting customers' homes

Strong answer

Visits, listens, documents it, arranges cleaning or repair, and resets the crew's habits on floor protection and dust control.

Red flags

Argues about whether the damage was already there.

Tell me about a time an experienced plumber's work failed your check, like a back-pitched drain, and you had to get it redone.

Behavioral · Correcting an experienced plumber

Strong answer

Focused on the specific work and the code or standard, listened, agreed on the fix, and kept the relationship.

Red flags

Avoided it, or corrected them in front of the customer.

Tell me about a day several of your jobs went wrong at once, like a leak after a repipe and a failed rough-in inspection. How did you decide where to go first?

Behavioral · Running several jobs

Strong answer

Ranked them by safety, water damage and customer impact, talked a plumber through what could be handled by phone, went where they were most needed, and kept everyone updated.

Red flags

Went wherever the last call came from, or left water running at one job while handling another.

Your state requires apprentices to log work hours and classes toward a journeyman license. How do you support that?

Situational · Apprentice licensing support

Strong answer

Tracks hours and classroom requirements, works with schools, makes sure apprentices are supervised as the state requires, and ties raises or promotions to progress.

Red flags

Leaves it to each apprentice to figure out.

Walk me through a new plumber's first week from an HR point of view.

Technical · Onboarding field staff

Strong answer

I-9 and payroll forms on time, license verification, safety training, vehicle and driving policy, truck and tool checkout, a ride-along schedule and a check-in at week's end.

Red flags

Paperwork on day one and nothing after.

A plumber hurts their back carrying a water heater down basement stairs. What do you do?

Situational · Injury response

Strong answer

Makes sure they get care, reports the claim to the insurance carrier promptly, records it as OSHA requires, looks at lifting practices and equipment like stair dollies, and stays in touch about return to work.

Red flags

Waits to see if the injury gets better before reporting it.

Two apprentices tell you a field supervisor yells at them and threatens their hours. What do you do?

Situational · Complaints about a supervisor

Strong answer

Documents the complaints, investigates with interviews, reaches a finding, takes action consistent with policy, and protects the apprentices from retaliation.

Red flags

Tells them that's how the trade is.

Tell me about a time exit or stay interviews with plumbers led you to change something that cut turnover.

Behavioral · Improving retention

Strong answer

Names what they heard, such as on-call load, supervisors or slow apprentice progress, the specific change they made, and how they measured retention afterward.

Red flags

Has no data, or just raised pay without knowing why people left.

Tell me about a time a top plumber broke a safety or vehicle policy and their manager wanted an exception.

Behavioral · Applying policy fairly

Strong answer

Applied the policy the same way as for anyone else, handled the manager's pushback, and explains why consistency matters for fairness and legal risk.

Red flags

Made an exception because the plumber brings in revenue.

Walk me through how you'd make sure the company shows up when someone nearby searches for an emergency plumber.

Technical · Emergency search visibility

Strong answer

Keeps business profiles accurate with hours and service areas, earns and answers reviews, builds service and area pages, and runs paid search on emergency terms with call tracking.

Red flags

Posts on social media and hopes.

The owner wants more referrals from real estate agents and home inspectors. How do you build that?

Situational · Building referral partners

Strong answer

Finds the most active agents and inspectors, offers something useful like fast sewer camera inspections with clear reports, sets up a simple referral process and tracks results.

Red flags

Sends a mass email to agents.

A manager suggests giving customers a discount for leaving five-star reviews. What do you advise?

Situational · Honest reviews

Strong answer

Explains that review sites and FTC rules prohibit buying reviews or rewarding only positive ones, and sets up a process to ask every customer for an honest review.

Red flags

Goes along with it because competitors do it.

Calls slow down in late spring and spike with every freeze. How do you plan marketing around that?

Situational · Planning around weather

Strong answer

Keeps search presence steady, pushes drain, water heater and maintenance offers in slow periods, prepares freeze messaging ahead, and matches spend to the team's capacity.

Red flags

Spends the same every month, or goes dark when it's slow.

Tell me how you decided to stop using a marketing channel, such as a shared-lead service or direct mail.

Behavioral · Learning from failure

Strong answer

Gives the numbers, how long they tested it, and what they moved the money to.

Red flags

Dropped it on a feeling, or never stops anything.

Tell me about a time you had to get the field team to represent the brand better, such as truck appearance or how technicians introduce themselves.

Behavioral · Brand consistency

Strong answer

Explains why it mattered, how they worked with operations, and how they checked it stuck.

Red flags

Sent a memo and moved on.

Walk me through how you'd track permits and inspections on water heater and sewer jobs.

Technical · Permit and inspection tracking

Strong answer

Logs each permit by job, tracks inspection dates and results, follows up on failures, and makes sure every permit gets closed.

Red flags

Lets each plumber keep track of their own permits.

Technicians keep leaving finished jobs without collecting payment. What do you do?

Situational · Payment at time of service

Strong answer

Finds out why (customer pushback, unclear policy, software problems), fixes the process with the service manager, trains technicians, and tracks uncollected jobs weekly.

Red flags

Sends more invoices and hopes customers pay.

A homeowner's insurer asks for an itemized invoice and photos for a water damage claim. What do you do?

Situational · Insurance documentation

Strong answer

Gathers the technician's notes and photos, prepares an accurate itemized invoice, sends it promptly, and keeps the homeowner informed.

Red flags

Sends the standard invoice and waits for the insurer to ask again.

The phone system goes down on a busy morning after a freeze. What do you do?

Situational · Keeping the office moving

Strong answer

Switches to backup lines or forwarding, posts a message on the website and profiles, tells dispatch and technicians, and calls the provider.

Red flags

Waits for the phones to come back.

Tell me about a change you made that got job paperwork, permits or invoices closed out faster.

Behavioral · Closing out jobs faster

Strong answer

Names the bottleneck (missing tickets, unclosed permits, late invoices), the change, how they got technicians on board, and a before-and-after measure.

Red flags

Can't point to anything they changed, or the change made more work for the field.

Tell me about a time you trained a new customer service rep or office hire on booking and billing plumbing jobs.

Behavioral · Leading office staff

Strong answer

Gave a clear plan, practiced real call types like leaks and backups, checked their work, gave honest feedback, and helped them work on their own.

Red flags

Left them to learn by trial and error.

Your drain technicians are slammed this week, and your repipe crew is waiting on materials. What do you do?

Situational · Balancing work types

Strong answer

Moves qualified repipe plumbers to service calls they can handle, checks truck equipment, chases the materials, and tells affected customers new dates.

Red flags

Leaves the repipe crew idle.

Walk me through how you'd measure and improve how often service calls turn into approved work.

Technical · Measuring conversion

Strong answer

Tracks approved options by technician and job type, rides along, coaches diagnosis and how options are presented, and checks pricing, without rewarding pressure.

Red flags

Sets a conversion target and leaves it there.

Callbacks on drain cleanings are high. What do you look at?

Situational · Drain callbacks

Strong answer

Whether technicians use the right cable size or jetting, whether they camera the line to find root causes, and whether customers are told about underlying problems.

Red flags

Tells technicians to run the cable longer.

Two trucks were broken into last month and expensive tools were stolen. What do you do?

Situational · Protecting tools and trucks

Strong answer

Reviews how tools are stored and where trucks are parked overnight, adds locks or tracking, checks insurance, and sets a check-in and check-out routine.

Red flags

Tells technicians to be more careful.

Tell me about a time your team let a customer down, like a missed no-water call or a leak after a repair, and you won them back.

Behavioral · Recovering a customer

Strong answer

Called personally, owned it, fixed the problem, offered something fair, and changed the process.

Red flags

Left it to the office, or offered a discount without fixing what went wrong.

Tell me about a change you made to scheduling, such as realistic times for drain, water heater and repipe work, that helped plumbers run more calls without rushing.

Behavioral · Improving scheduling

Strong answer

Names the change (zones, realistic job times, buffer for emergencies), how they measured calls per day and callbacks, and the result.

Red flags

Packed more calls into the day and callbacks rose.

Walk me through planning a front-yard sewer line replacement from the signed contract to final inspection.

Technical · Planning a sewer replacement

Strong answer

Permit, utility locates, the excavation plan and trench protection, equipment, city connection and inspection before backfill, telling the homeowner about the yard, and restoration.

Red flags

Sends the crew with a digger and figures it out on site.

You're repiping a home where the family needs water every night. How do you plan the job?

Situational · Repiping occupied homes

Strong answer

Works in sections so water is back each evening, protects floors and belongings, plans the drywall patches, and updates the family daily.

Red flags

Shuts the water off for the whole job.

An inspector fails a sewer replacement because the slope is wrong in one section, and the trench is still open. What do you do?

Situational · Inspection failures

Strong answer

Gets the crew to fix it right away while it's exposed, schedules the reinspection, tells the customer, and checks why the slope wasn't verified before calling.

Red flags

Argues with the inspector or backfills anyway.

A key fitting for a repipe is backordered and the crew starts tomorrow. What do you do?

Situational · Material shortages

Strong answer

Checks other suppliers and approved alternatives, adjusts the plan if it can, and tells the customer honestly before the crew shows up.

Red flags

Sends the crew and hopes it arrives.

Tell me about a time you made a crew's excavation or trench work safer.

Behavioral · Excavation safety leadership

Strong answer

Names the hazard, the change (trench boxes, a competent person on site, locates), how they got buy-in, and how they kept it in place.

Red flags

Says nobody has been hurt so it's fine.

Tell me about a crew whose jobs kept running over the estimated hours, like repipes where opening walls took longer than planned. What did you do?

Behavioral · Crew accountability

Strong answer

Looked at the causes (estimates, crew skills, missing material), fixed the right thing, and tracked the next jobs.

Red flags

Blamed the crew without looking at the estimates.

Your top seller's close rate is unusually high, and two customers say they felt rushed into signing. What do you do?

Situational · Commission plans and conduct

Strong answer

Reviews the jobs and talks with the customers, rides along, coaches or acts on the seller, and makes sure the pay plan doesn't reward pressure.

Red flags

Ignores it because the numbers are strong.

Your team closes water heaters well but almost never sells water treatment, even when tests show a need. What do you do?

Situational · Coaching on a product line

Strong answer

Checks whether reps understand the products and test results, trains with real cases, rides along, and makes sure recommendations follow the test, not a quota.

Red flags

Sets a water treatment quota.

A rep sold a sewer replacement with a start date the production team can't meet. What do you do?

Situational · Selling what operations can deliver

Strong answer

Gets the real date from production, calls the customer with the rep to reset it honestly, and fixes how reps confirm dates before promising them.

Red flags

Leaves it for production to explain.

Walk me through how you'd set up the sales pipeline so you can forecast project sales for the next month.

Technical · Building the pipeline

Strong answer

Defines stages, records every estimate with value and date, uses past close rates by job type and source, and reviews each open deal's next step weekly.

Red flags

Asks reps what they think will close.

Tell me about a practice exercise you've used to test sales candidates, like presenting repipe options to a skeptical homeowner.

Behavioral · Hiring salespeople

Strong answer

Describes the role-play or practice estimate, what they looked for, such as honest options and good questions, and how well it predicted who succeeded.

Red flags

Relies on a good conversation, confidence and references.

Tell me about a time you had to make things right with a customer after a salesperson oversold, like a water treatment system the water test didn't support.

Behavioral · Handling complaints

Strong answer

Listened, got the facts, offered a fair fix, addressed it with the salesperson, and changed something to prevent repeats.

Red flags

Defended the sale without checking.

Water heaters keep getting dented or damaged in the warehouse before they reach jobs. What do you do?

Situational · Protecting stock

Strong answer

Finds where it happens (receiving, storage, loading), sets proper stacking and handling rules, adds equipment like hand trucks or straps, and trains the team.

Red flags

Writes it off as normal damage.

Walk me through how you'd set minimum and maximum stock levels for the warehouse.

Technical · Reorder points

Strong answer

Uses usage history, supplier lead times and seasonal swings like freeze events, ranks parts by value and impact, and reviews levels on a schedule.

Red flags

Orders when shelves look low.

Your receiver signed for a delivery without counting, and now jobs are short. What do you do?

Situational · Receiving errors

Strong answer

Gets the shortage documented and claimed with the supplier, covers the jobs, retrains on counting before signing, and checks receiving for a few weeks.

Red flags

Blames the receiver and changes nothing.

Plumbers are leaving late every morning because restocking takes too long. What do you do?

Situational · Early-morning truck restocks

Strong answer

Times the process, has restock pulled the night before from usage reports, organizes the most-used parts near loading, and measures departure times.

Red flags

Tells plumbers to come in earlier.

Tell me about a time you got your team to keep fittings, valves and pipe organized so plumbers could find them fast.

Behavioral · Leading the warehouse team

Strong answer

Set a clear system, trained it, checked it regularly, and recognized people who kept it up.

Red flags

Cleaned it up themselves once.

Tell me about a time you cleaned out slow-moving plumbing stock, like valves from a brand you no longer use or fittings for retired tools.

Behavioral · Clearing dead stock

Strong answer

Found dead stock from usage data, returned what they could for credit, sold or wrote off the rest with approval, set rules so it doesn't pile up again, and protected must-have emergency parts.

Red flags

Keeps everything just in case, or dumped stock without trying returns or credits.

A caller says water is pouring through their kitchen ceiling from the bathroom above. What do you tell them while you book the call?

Situational · Active leak calls

Strong answer

Walks them to the main water shutoff, tells them to stay away from wet light fixtures and outlets, books an emergency visit, and gives an honest arrival time.

Red flags

Just books the next opening without helping stop the water.

A caller says they smell gas near their water heater. What do you do?

Situational · Gas smell calls

Strong answer

Tells them to leave the house without using switches, and to call the gas utility or 911 from outside, follows the company safety script, and alerts dispatch.

Red flags

Books it as a routine water heater call.

A caller says sewage is coming up in their basement shower. What do you ask before booking?

Situational · Sewer backup details

Strong answer

Which fixtures are affected, whether it's getting worse, whether they know of a cleanout, city sewer or septic, and tells them to stop running water until the plumber arrives.

Red flags

Books it with no details.

A caller wants a price to replace their water heater before anyone looks at it. What do you say?

Situational · Price questions

Strong answer

Gives only the price guidance the company approves, explains that type, size, venting and code updates affect the price, and offers a visit for an exact quote.

Red flags

Makes up a number, or refuses to talk about price at all.

Tell me about a time you calmed down a customer who was upset about a plumbing bill, such as a drain call that cost more than they expected.

Behavioral · Handling billing complaints

Strong answer

Listened, got the facts, explained the charges plainly, brought in a manager when needed, and followed up.

Red flags

Argued, or promised a refund they couldn't authorize.

Tell me about a time you caught a booking mistake before a plumber went out, like the wrong address or a gas job booked as a drain call.

Behavioral · Accuracy under pressure

Strong answer

Describes the habit that caught it, such as reading back the address and job type, and what they did to fix it.

Red flags

Has no habit for checking their work, like reading back addresses or confirming the job type, and counts on others to catch errors.

It's Monday after a hard freeze. Burst pipe calls keep coming in and the board is already full of drain cleanings. Walk me through how you sort the day.

Situational · Sorting the day after a freeze

Strong answer

Puts active leaks the customer can't stop first, then no-water calls, moves routine drain and fixture work with honest calls to those customers, and keeps trucks stocked for freeze repairs.

Red flags

Works calls in order, or moves customers without telling them.

A main line backup comes in, and the closest plumber doesn't have a jetter or camera on the truck. What do you do?

Situational · Matching equipment to the call

Strong answer

Sends the nearest plumber with the right equipment, or arranges for equipment to meet the job, and gives the customer a real arrival time.

Red flags

Sends the closest plumber anyway.

A water heater swap turns into a gas line repair that will take the rest of the day. What do you do?

Situational · Jobs that grow

Strong answer

Reassigns the plumber's afternoon calls to qualified techs, calls those customers before their windows pass, and updates the board right away.

Red flags

Waits to see if the job wraps up, leaving customers in the dark.

Walk me through how you'd plan routes for six plumbers covering a large service area.

Technical · Route planning

Strong answer

Groups calls by zone, puts long jobs early, leaves buffer for emergencies, keeps one plumber flexible, and updates routes as calls come in.

Red flags

Assigns calls in the order they were booked.

Tell me about a time you kept a customer informed while they waited without water, such as during a parts delay or a freeze rush.

Behavioral · Keeping customers informed

Strong answer

Called before they had to ask, gave real times, offered options, and followed through.

Red flags

Waited for the customer to call in.

Tell me about a time a plumber pushed back on a job you sent them to, like a sewer backup across town late in the day.

Behavioral · Working with technicians

Strong answer

Listened, explained the reasoning, changed it if the plumber had a point, and kept the relationship good.

Red flags

Ignored the technician, or changed the whole day to avoid conflict.

Technicians collect card, check and cash payments in customers' homes. Walk me through how you reconcile a day's field payments to the bank.

Technical · Reconciling field payments

Strong answer

Matches each payment in the field software to its invoice, totals by payment type, ties card batches and deposits to the bank, and chases any gap with the technician that week.

Red flags

Records the bank deposit total without matching it to invoices.

A homeowner's insurance company sends a check for water damage repairs made out to both the homeowner and your company. What do you do?

Situational · Two-party insurance checks

Strong answer

Doesn't deposit it without both endorsements, works with the homeowner to get theirs, applies it to the right invoice, and tracks any balance the homeowner still owes.

Red flags

Deposits it with only the company's endorsement, or sets it aside and forgets it.

You notice the same supply house invoice was entered twice and paid twice last month. What do you do?

Situational · Catching duplicate payments

Strong answer

Confirms with the supplier, asks for a credit or refund, documents it, tells their manager, and adds a duplicate check before payments go out.

Red flags

Waits for the supplier to notice, or quietly deletes one entry.

A technician's fuel card shows fill-ups on a Sunday when they weren't on call. What do you do?

Situational · Questioning expenses neutrally

Strong answer

Checks schedules and on-call logs first, asks the technician and their manager without accusing, and reports what they find to management.

Red flags

Accuses the technician, or ignores it.

Tell me about a mistake you made in the books, such as a payment applied to the wrong invoice or a supply house bill coded to the wrong job.

Behavioral · Owning errors

Strong answer

Names the mistake, told their manager, corrected it with documentation, and changed a step to prevent repeats.

Red flags

Says they don't make mistakes, fixed it quietly without telling anyone, or can't say what step they changed.

Tell me about a time you had to close the month while chasing missing field paperwork, like unsigned tickets or unreported payments.

Behavioral · Closing with field paperwork

Strong answer

Explains how they prioritized, who they chased and how, what they told their manager about timing, and how the books closed accurately.

Red flags

Closed with known gaps and told no one.

A hard freeze is forecast for this weekend. What do you do with stock today?

Situational · Freeze preparation

Strong answer

Checks levels of repair couplings, pipe, fittings and valves, orders before suppliers run short, stages extra for trucks, and tells the service manager what's ready.

Red flags

Waits until technicians start asking.

Walk me through how you'd decide how many water heaters of each type and size to keep in stock.

Technical · Water heater stock levels

Strong answer

Uses sales history by size, fuel and venting type, supplier lead times, storage space and the cash tied up, and sets minimum and maximum levels it reviews monthly.

Red flags

Keeps whatever the supplier recommends.

Technicians say the supplier keeps sending PEX fittings that don't match the company's tools. What do you do?

Situational · Matching fittings to tools

Strong answer

Checks orders and part numbers, sets an approved parts list, raises it with the supplier, and checks fittings at receiving.

Red flags

Tells technicians to make it work.

A truck audit shows one plumber's truck is missing parts that were never billed. What do you do?

Situational · Truck stock audits

Strong answer

Checks the records first, asks the plumber for unrecorded jobs or warranty swaps, fixes how parts are recorded, and reports any pattern to the manager.

Red flags

Accuses the plumber without checking.

Tell me about a time you tracked down why a truck or warehouse count of fittings or water heaters was off.

Behavioral · Finding count differences

Strong answer

Traced the transactions to the cause, corrected it with notes, and changed a step to prevent repeats.

Red flags

Just adjusted the number without finding the cause.

Tell me about a time you got a supply house to stop shorting orders or sending the wrong parts.

Behavioral · Vendor problems

Strong answer

Documented the pattern, went to the right contact, agreed on a fix and checked that it held.

Red flags

Complained but kept accepting the errors.

Walk me through how you'd estimate a whole-house repipe.

Technical · Estimating a repipe

Strong answer

Counts fixtures and floors, chooses material and routes, plans wall openings and drywall repair, includes the permit and crew days, and checks the plan with operations.

Red flags

Uses a price per bathroom without seeing the house.

A homeowner asks if a water softener will make their water safe to drink. What do you tell them?

Situational · Honest water treatment advice

Strong answer

Explains that a softener removes hardness minerals but doesn't disinfect or remove most contaminants, suggests a water test, and recommends only what the results support.

Red flags

Says yes to make the sale.

A camera inspection shows one broken section of an otherwise sound sewer line. The homeowner expected to replace it all. What do you recommend?

Situational · Repair over replace

Strong answer

Shows the footage, explains a spot repair and a full replacement with honest prices and risks, and recommends what fits the line's condition.

Red flags

Recommends full replacement because it's the bigger sale.

After seeing your camera footage, a homeowner says they want other quotes on the sewer replacement. What do you leave them with?

Situational · Respecting the decision

Strong answer

Offers a copy of the footage and a written scope, such as length, depth, method and restoration, so quotes compare fairly, answers questions, sets a follow-up time and logs notes.

Red flags

Offers a discount that expires today, won't share the footage, or runs down other contractors.

Tell me about a repipe, sewer or water treatment project you expected to win but lost.

Behavioral · Learning from lost sales

Strong answer

Reflects honestly on what they missed (needs, trust, how options were presented, follow-up) and names what they do differently now.

Red flags

Blames the price.

Tell me about a time the crew found something on a job you sold that wasn't in your estimate.

Behavioral · Owning the handoff

Strong answer

Owned it, helped work it out with the crew and customer, and changed how they inspect before quoting.

Red flags

Said it was the crew's problem.

Two months ago a homeowner declined a sewer line replacement after a camera inspection. What does your first call sound like?

Situational · Following up on a declined sewer job

Strong answer

Reviews the notes and footage first, asks how the line has been, offers to explain the footage again or discuss options like lining or a spot repair, and keeps it low-pressure.

Red flags

Opens with a discount or tells them the line could collapse any day.

The homeowner says they'll wait until it backs up again. What do you say?

Situational · Handling wait-and-see

Strong answer

Respects it, explains honestly the risks and the cost difference between a planned and an emergency repair, offers a maintenance cleaning, and leaves the decision to them.

Red flags

Uses scare tactics, or hangs up without offering anything.

A coworker suggests telling customers that permit fees go up next month to create urgency, but you don't know if that's true. What do you do?

Situational · Truthful urgency

Strong answer

Won't say anything they can't verify, checks the facts, and uses real reasons to follow up.

Red flags

Says it because it might work.

Walk me through how you'd decide which declined plumbing estimates to call first when the list mixes sewer replacements, water heaters and repipes.

Technical · Working the lead list

Strong answer

Weighs how likely the problem is to get worse, such as camera findings or an aging, leaking tank, plus estimate age, why they declined and whether a cheaper option exists, then sets follow-up dates and logs every outcome.

Red flags

Calls the biggest dollar amounts first no matter the notes, or works the list top to bottom.

Tell me about a homeowner who declined a sewer or water heater job and later booked it with you.

Behavioral · Recovering lost sales

Strong answer

Explains how they learned the real reason, what new information or option helped, and that the customer was happy with the decision.

Red flags

Describes calling until the customer gave in.

Tell me about a time you closed out a plumbing lead for good, like a homeowner who hired someone else for the sewer job.

Behavioral · Respecting a final no

Strong answer

Recognized a real reason, ended it politely, noted why, and left the door open.

Red flags

Never closes leads, or gives up after one call.

You're helping dig a trench for a sewer line. It's getting deep and the loose dirt on the sides keeps caving in. What do you do?

Situational · Trench safety

Strong answer

Gets out and stays out, tells the plumber right away, and waits until a competent person checks it and shoring, sloping or a trench box is in place.

Red flags

Keeps digging so they don't look slow.

You glued a PVC fitting facing the wrong way, and the plumber hasn't noticed. What do you do?

Situational · Owning mistakes

Strong answer

Tells the plumber right away so it can be cut out and redone before more work is built on it.

Red flags

Hopes it doesn't matter, or hides it.

While the plumber is at the truck, the homeowner asks you how much the job is going to cost. What do you say?

Situational · Customer questions

Strong answer

Is friendly, explains that the plumber will go over the price, and passes the question along.

Red flags

Guesses a number, or ignores the homeowner.

In your own words, walk me through how water gets to a kitchen faucet and where it goes after it drains.

Technical · How a plumbing system works

Strong answer

Describes pressurized supply from the city main or a well through shutoff valves, and drains flowing by gravity through a trap to the sewer or septic, maybe mentioning vents. Rough is fine.

Red flags

Mixes up supply and drain, like thinking drains run under pressure, can't name a shutoff or trap, and shows no interest in finding out.

Tell me about something you fixed or built with your hands, like a running toilet, a bike or a piece of furniture, at work, school or home.

Behavioral · Learning by doing

Strong answer

Describes the project, how they figured it out, a mistake they made, and what they'd do differently.

Red flags

Can't explain how they figured out any step, describes only watching someone else do it, or blames the tool for what went wrong.

Tell me about a time at work, school or volunteering when a group counted on you to be ready early, like loading a truck or opening up before others arrived.

Behavioral · Reliability

Strong answer

Gives a specific example, explains why it mattered, and describes how they planned to be on time.

Red flags

Can't think of an example, or treats being late as no big deal.

Walk me through replacing a gas tank water heater so it passes inspection.

Technical · Water heater replacement

Strong answer

Pulls the permit, shuts off gas and water, checks the vent, pipes the relief valve discharge to code, adds an expansion tank, sediment trap and straps where required, leak-tests the gas, fills before lighting, and confirms draft once it runs.

Red flags

Swaps the tank and reconnects the old fittings without checking venting or relief valve piping.

The kitchen sink and the basement floor drain both back up when the washer drains. Walk me through how you diagnose it.

Technical · Drain diagnosis

Strong answer

Asks about history, checks which fixtures are affected to locate the blockage, opens the cleanout, clears it with the right cable or jetter, and runs a camera to find the cause.

Red flags

Snakes the kitchen sink and leaves.

You arrive at a home with water pouring through the ceiling and the homeowner can't find the main shutoff. What do you do?

Situational · Emergency response

Strong answer

Finds and closes the main or curb stop fast, keeps people away from wet electrical, finds the source, explains next steps including drying, and documents it for insurance.

Red flags

Starts the repair before stopping the water.

After cleaning a main line, the camera shows roots in an old clay sewer line, but it's flowing fine. The homeowner asks if they need a new line. What do you say?

Situational · Honest recommendations

Strong answer

Shows the footage, explains the options honestly (maintenance cleaning, lining or replacement) with risks and costs, and lets them decide.

Red flags

Says it must be replaced today, or says it's fine when it isn't.

Think of the last time an inspector failed your work. What did you change in how you work afterward?

Behavioral · Learning from inspections

Strong answer

Names the code issue plainly and a specific habit they changed, such as checking slope or nail plates before calling for inspection.

Red flags

Says the inspector was wrong, or claims they've never failed one.

Tell me about a time a plumbing job caused damage in someone's home, like water on a floor or a wall opened wider than planned. What did you do?

Behavioral · Respecting the home

Strong answer

Told the customer right away, owned it, made it right, and changed a habit such as using drop cloths and shoe covers.

Red flags

Hoped the customer wouldn't notice.

Walk me through how you size and lay out the drain, waste and vent piping for a bathroom addition.

Technical · Drain, waste and vent design

Strong answer

Uses fixture unit values from the code in force to size drains and vents, plans trap arms, slope, vent connections and cleanouts, ties into the existing system, and checks local amendments.

Red flags

Copies what's already there or guesses sizes.

A homeowner is adding a tankless water heater and a gas range. Walk me through how you plan the gas piping.

Technical · Gas line sizing

Strong answer

Totals the load of all appliances, measures run lengths, sizes pipe from the code tables for the supply pressure, checks meter capacity with the utility, and pressure tests the system.

Red flags

Tees into the nearest line without checking capacity.

A journeyman you supervise keeps installing S-traps on remodels because the old house had them. How do you handle it?

Situational · Coaching on code

Strong answer

Explains why current code doesn't allow them (they siphon the trap seal), shows the right setup, and checks their next jobs.

Red flags

Fixes them quietly without explaining, or lets it go.

Your license is on the permit, and you find a crew drywalled over work before the rough-in inspection. What do you do?

Situational · Protecting the permit

Strong answer

Stops further work, has the wall opened for inspection, is honest with the inspector, and addresses it with the crew.

Red flags

Hopes the inspector doesn't ask.

Tell me about a standard procedure you wrote or changed that cut callbacks, such as a pressure-test or water heater install checklist.

Behavioral · Writing standard procedures

Strong answer

Names the problem, the procedure, how they trained people on it, and the measured result.

Red flags

Has never written one, or can't say whether it helped.

Tell me how you handled a big job, such as a repipe or sewer replacement, where your estimate missed badly.

Behavioral · Estimating accuracy

Strong answer

Told the right people early, handled the customer honestly, and changed how they estimate.

Red flags

Blames the crew or the customer.