A plumber installs, maintains, and repairs pipes that carry water, gas, and other liquids. They do this by installing or replacing fixtures like sinks, toilets, dishwashers, and showers with the appropriate piping connections. Plumbers might also fix problems where these pipes connect to things like garbage disposals.
A plumber might also repair and maintain water heaters, gas lines, or heating systems. In addition to installing pipes, a plumber will often install sinks in new homes and replace existing plumbing fixtures that are old or broken.
As a hiring manager, it is important to be prepared when interviewing a potential job candidate.
Since you want to hire the most qualified person possible, it is advisable to review your company’s job description and qualifications before setting up a time for an interview. This will help you determine what kind of skills this position requires and how best to match them with the interviewing candidates. It also helps in evaluating whether or not this is a good opportunity for the candidate.
It is also important to prepare for an interview by researching the individual that you are interviewing. This way, you can be more prepared with questions and have background information on your potential hire.
Essential Interview Questions
What plumbing license do you have?
Listen fora valid state plumbing license and knowledge of local regulations
How long have you worked as a plumber?
Listen forextensive hands-on experience with various plumbing systems and techniques
Do you have experience working on residential or commercial plumbing systems?
Listen forspecific examples of projects handled in both residential and commercial settings
What safety measures do you take when working on a plumbing system?
Listen forknowledge of safety protocols and personal protective equipment usage
How do you prioritize tasks when you have several customers at the same time?
Listen fora clear strategy for managing multiple jobs based on urgency and customer needs
How do you respond to plumbing emergencies?
Listen fora systematic approach to assessing and resolving urgent plumbing issues quickly
Why are you interested in working for our company?
Listen foralignment of personal values with company mission and a desire for growth
Rate each answer as you hear it, not from memory afterwards. Use the same scale for every candidate so the notes stay comparable.
Plumber · Candidate Scorecard
Score every candidate against the same six criteria, so two interviewers reach comparable conclusions instead of competing impressions.
Plumbing Code Knowledge
understanding of local plumbing codes and compliance requirements
Pipe Fitting Skills
expertise in cutting, bending, and joining various pipe materials
Fixture Installation
ability to install and repair plumbing fixtures efficiently
Drainage Systems
knowledge of drainage design and troubleshooting techniques
Water Heater Repair
experience in diagnosing and fixing water heater issues
Customer Service
ability to communicate effectively and address customer concerns
Take this scorecard into the interview
Download the fillable PDF, or have it emailed to you with all 7 questions attached.
Plumber Job Description
Take a look at what key requirements, duties, responsibilities, and skills should be part of your Plumber job description.
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Frequently Asked Questions
How many interview questions should I ask?
Plan for 5–7 core questions in a 45–60 minute interview. This allows time for follow-up questions and gives candidates space to provide detailed examples.
What are red flags during an interview?
Watch for vague answers, lack of specific examples, blame-shifting, or inability to explain their role in past results.
How do I evaluate interview answers objectively?
Use a consistent scoring rubric for each question and focus on measurable examples and demonstrated skills.
Do structured interviews improve hiring results?
Yes. Structured interviews increase consistency, reduce bias, and make it easier to compare candidates fairly.
How do I assess technical skills without a hands-on test?
Ask candidates to walk through their diagnostic process for common problems, explain how they use specific tools, and describe recent challenging repairs they completed successfully.
Plumber Job Description Template
These questions are written against the same role definition. Post the job description first, then interview from this scorecard, and the criteria you screened on are the criteria you score on.