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Free Plumber Interview Scorecard

Print one per candidate. Questions are grouped by area, each with a 1 to 5 rating and room for notes, so a service manager and a lead plumber rating two different candidates produce something comparable. The answer key for every question is on the interview questions page.

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Plumber interview scorecard

Reviewed September 8, 2026 · tradegrader.ai

Candidate
Interviewer
Date
Role being filled ServiceDrainNew constructionCommercial serviceApprenticeLead / foreman

Diagnosis

A customer has lukewarm water at every fixture and it runs out faster than it used to. Eight-year-old gas heater, lighting and staying lit. Where do you start?

Best for: Service, commercial

Rate 12345

How do you tell whether a recurring drain problem is the fixture, the branch, or the main?

Best for: Service, drain

Rate 12345

Tell me about a call you misdiagnosed.

Best for: All roles

Rate 12345

Code and systems

Why does a fixture need a vent?

Best for: All roles

Rate 12345

What have you run into working on older buildings that doesn't come up on new work?

Best for: Service, drain

Rate 12345

When does a job you're on need a permit and an inspection?

Best for: All licensed roles

Rate 12345

Gas and safety

Walk me through what you do before and after a water heater replacement on the gas side.

Best for: Service, commercial

Rate 12345

You find a condition that isn't safe and the customer doesn't want to pay to fix it. What happens?

Best for: All roles

Rate 12345

Customer-facing judgment

How do you present options when the right repair is the expensive one?

Best for: Service, drain

Rate 12345

You find previous work that's dangerous. How do you talk to the customer about it?

Best for: All customer-facing roles

Rate 12345

Their last shop

What was your split between service, drain, and new construction?

Best for: All roles

Rate 12345

What would have kept you?

Best for: All roles

Rate 12345

How were you dispatched and how was your work reviewed?

Best for: Service, drain, commercial

Rate 12345
Overall rating (1 to 5)
Recommendation
What would you still want to know?