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Plumber interview questions and answers

This is a sample of Plumber interview questions to ask your candidates. These interview questions can help you evaluate their qualifications and find the perfect fit for your company.

Christina Pavlou
Christina Pavlou

An experienced recruiter and HR professional who has transferred her expertise to insightful content to support others in HR.

plumber interview questions

10 good plumber interview questions

  1. What license do you have as a plumber?
  2. Have you ever plumbed an office building?
  3. If you had to install a new system for an entire floor of a building, where would you start?
  4. What is the first thing you look at before you design a plumbing system?
  5. Do you have any experience installing water-based heating systems?
  6. Walk us through the installation of a gas and liquid heating system, like an air-conditioning unit.
  7. If a customer complains their house has too little water pressure, what steps would you take to fix the problem?
  8. If a customer needs a new toilet installed, you remove the old one and discover the floor is rotting, what do you do?
  9. How do you prioritize when dealing with different customers at the same time?
  10. What safety precaution measures do you take when installing or maintaining a plumbing system?

Here are 10 essential interview questions and sample answers to help identify the best candidates for this role.

1. What license do you have as a plumber?

This question helps to verify the candidate’s qualifications and legal ability to work as a plumber.

Sample Answer:

“I have a Journeyman Plumber License, which I obtained after completing my apprenticeship and passing the state exam.”

2. Have you ever plumbed an office building?

This question assesses the candidate’s experience in commercial plumbing projects.

Sample Answer:

“Yes, I have worked on plumbing systems for multiple office buildings, including both installation and maintenance tasks.”

3. If you had to install a new system for an entire floor of a building, where would you start?

This question tests the candidate’s planning and organizational skills.

Sample Answer:

“I would start by assessing the building’s blueprints and identifying the water supply and drainage points. Then, I’d create a detailed plan for the installation.”

4. What is the first thing you look at before you design a plumbing system?

This question evaluates the candidate’s approach to designing a plumbing system.

Sample Answer:

“The first thing I consider is the building’s layout and the specific plumbing needs based on its usage, like the number of bathrooms, kitchens, etc.”

5. Do you have any experience installing water-based heating systems?

This question gauges the candidate’s expertise in specialized plumbing tasks.

Sample Answer:

“Yes, I have experience installing water-based heating systems, including radiant floor heating and hydronic systems.”

6. Walk us through the installation of a gas and liquid heating system, like an air-conditioning unit.

This question tests the candidate’s technical knowledge and ability to explain complex procedures.

Sample Answer:

“First, I would identify the optimal location for the unit, then proceed with installing the gas lines, followed by the liquid lines, ensuring all connections are secure.”

7. If a customer complains their house has too little water pressure, what steps would you take to fix the problem?

This question assesses the candidate’s problem-solving skills.

Sample Answer:

“I would first check the water meter and main shut-off valve, then proceed to inspect the water lines and pressure regulator to identify the issue.”

8. If a customer needs a new toilet installed, you remove the old one and discover the floor is rotting, what do you do?

This question evaluates the candidate’s ability to handle unexpected challenges.

Sample Answer:

“I would immediately inform the customer about the issue and recommend repairing the floor before proceeding with the toilet installation.”

9. How do you prioritize when dealing with different customers at the same time?

This question tests the candidate’s time-management skills.

Sample Answer:

“I prioritize based on the urgency of the issue and the scheduling commitments I have made to each customer.”

10. What safety precaution measures do you take when installing or maintaining a plumbing system?

This question assesses the candidate’s focus on safety.

Sample Answer:

“I always wear protective gear and follow safety guidelines, such as turning off the water supply and ensuring proper ventilation.”

What does a good plumber candidate look like?

A good plumber candidate should have a strong technical background, excellent problem-solving skills, and a focus on safety. They should also be able to communicate effectively with clients and team members.



Plumber Interview Questions

Plumbers are the people you call when you have a plumbing problem or want to install an hydraulic system. Hiring a plumber can be tricky since, apart from theoretical knowledge, you need people who respect safety precautions, work well in teams and have a good problem-solving attitude.

Requirements will vary depending on whether you’re hiring for an apprentice, a journeyman or a master plumber. Apprentices should be motivated and able to follow instructions to the letter. With other candidates, ask questions to determine their level of technical expertise and ability to solve problems. Master plumbers also need leadership skills and knowledge of regulations and processes (e.g. acquiring permits or building codes.)

Role-specific questions should be tailored according to the industry you operate in. For example, a plumber working in an industrial setting may need a different skillset than a service plumber. Additionally, plumbers employed by construction companies will need specialized knowledge such as installing complete hydraulic systems from scratch. The following plumber interview questions provide examples of how to assess candidates effectively.

Let’s summarize some of the questions and add a few more divided into specific types.

Operational and Situational questions

  • What license do you have as a plumber?
  • Have you ever plumbed an office building?
  • If you had to install a new system for an entire floor of a building, where would you start?
  • What is the first thing you look at before you design a plumbing system?
  • Do you have any experience installing water-based heating systems?
  • Walk us through the installation of a gas and liquid heating system, like an air-conditioning unit.
  • If a customer complains their house has too little water pressure, what steps would you take to fix the problem?
  • If a customer needs a new toilet installed, you remove the old one and discover the floor is rotting, what do you do?
  • How do you prioritize when dealing with different customers at the same time?
  • What safety precaution measures do you take when installing or maintaining a plumbing system?

Role-specific questions

  • What experience do you have with snaking clogged pipes?
  • Do you prefer your water mains to be PVC or copper?
  • What advantages do PVC water mains provide?
  • Have you ever installed a shower with multiple shower heads? How did you keep water pressure high?
  • What are the advantages for installing steel plumbing underneath a sink? In what cases would you do it?
  • Tell us about one downside of a conventional water heater. Would you suggest an alternative?

Behavioral questions

  • What is the worst thing you had to do as a plumber?
  • Tell us about your most challenging task and how you performed.
  • Describe a time you were given incomplete instructions about a project. What did you do?
  • Recall a time you offered excellent customer service as a plumber.
  • Describe a time you had to work in a team to complete a project. What was your role?

Pro tip: Licensure varies depending on location. Make sure you check the legal requirements and screen out candidates who don’t meet them. As the plumbing profession is often unionized, make sure you know about union guidelines before you hire.

Frequently asked questions

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