Top 15 Plumber interview questions & Answers (2021 Update)

1) Explain what is the primary step to unclog any blockage in the pipes?

First and primary technique to unclog the blockage is to pour hot water through the pipes. If the blockage still remains then, you need to use other options.

2) What is referred as Building Drain?

The lowest point in a drainage system where the interior drainage pipe meet and are conveyed into the sewer is referred as Building Drain.

3) List out some of the most common tools required for plumbing?

• Adjustable pipe wrench
• Faucet valve seat wrench
• Faucet valve reseating tool
• Faucet packing and washers
• Tubing cutter
• Teflon tape
• Cup plunger
• Flange plunger
• Closet Auger
• Sink Auger

4) What skills does a plumber should have?

• Problem solving
• Critical thinking
• Listening and paying attention to instruction
• Decision making
• Co-coordinating
• Technical knowledge related to pipe fitting

5) What all tools are required to unclog a sink?

• Cup Plunger
• Duct tape or wash cloth
• Sink Auger
• Channeled type pliers
• Bucket

Plumber

6) Mention what are the different types of chemical drain cleaners are used?

• Caustic drain cleaners: It contains a substance like caustic potash; they are bases and give electron to the clogging substance. This reaction will generate a lot of heat and dissolves the clogging substance, and clears the blockage.
• Oxidizing drain cleaners: It contains chemicals like household bleach, peroxides and nitrates. These chemical cause the organic material of the clog to lose an electron and become oxidized. It also generates heat and gas, which clears the blockage.
• Acid drain cleaners: It contains a higher concentration of acid and the hydronium ions present in acid reacts with clogging substance and releases heat. This heat will dissolve the substance and clears the blockage.

7) What is the home remedies to clear clogged drain?

The home remedies to clear clogged drain is

• Take half a cup of baking soda and pour down the drain, and then pour half a cup of vinegar. After 15 minutes, flush out the drain with hot water
• Add equal parts of salt, vinegar and baking soda. After one hour pour hot water into it
• Add half a cup of salt and equal amount of baking soda, sprinkle it into the drain and then flush it with hot water

8) Explain what is Angle Stop?

Angle stop is a shutoff valve between the water supply pipe and the fixture it supplies. It is used to shut off water to a fixture in case of failure, repair or leakage.

9) Mention what are some health and safety issues that plumber face?

Some of the health and safety risk that plumber face are

• Exposure to a hazardous substance like lead, sulfur dioxide, mould, carcinogenic substances
• Exposure to flammable and combustible materials
• Working in awkward positions may lead to musculoskeletal injuries
• Lifting heavy or awkward objects
• Risk of eye injury from flying particles
• Burns from hot equipment’s like steam lines, hot water heater, etc.
• Cut and bruises due to a sharp end of pipes
• Risk of electric shock while digging under-ground water pipes

10) What pre-caution a plumber could take for health and safety purpose?

• Avoid awkward body positions, and take break every 30 minutes
• Learn safe lifting techniques
• Wear appropriate footwear and gloves while handling sewage plant or metal pipes
• Keep tools and equipment’s in working condition, to avoid any unexpected accident due to inoperative tools
• To avoid electric shock use only power tools that can be used in a wet environment and have GFCI (Ground fault circuit interrupter).
• Keep work area clear

11) Explain what is the common reason for sump pump failure?

Sump pump is usually used in the basement area to remove the accumulated water during flood. Moreover, there are few reason it may stop working all of sudden.

• Switching problem
• Accumulation of excess debris, interfering with the switching
• The pump can move inside the basin, and that may interfere with the switching mechanism

12) Explain how you can fix a leaky PVC water pipe?

• Drain the water out and make the leakage pipe dry
• Now take a coupling, similar to the size of the pipe that is leaking
• Now cut the coupling into half
• Make sure that the half you going to use should have stop inside, as you have to slide the leakage pipe into it
• Slather the inside of the patch with adhesive, make sure that you have enough of the adhesive on your patch, as that is the portion that going to connect with the leaked pipe.
• Place the patch onto the pipe and slide it into place and keep it overnight to get dry

13) How can you avoid bathroom plumbing maintenance?

To avoid bathroom plumbing maintenance you can use the following tips

• Once a week flushes out the drainage pipes with hot water
• Apply pipe shield to drain lines once each month to keep soap scum building up and causing clogs
• To prevent further damage to the fixtures and faucets repair leaky faucets
• Showers and tubs should be fitted with strainers that can catch hair and soap chips
• Use vinegar to remove mineral deposit in your shower head, by placing a vinegar in a plastic bag and leave it over the shower head overnight. Take only 1 cup of vinegar.
• Throw the waste in wastebasket like tissue paper, cotton ball, etc.

14) Explain what is Pipe Dope?

A pipe dope is a pipe joint that is used to create a watertight seal.

15) Explain what is Eductor?

Eductor is a device that utilizes a nozzle and throat, fitted in a stream of water to build a partial vacuum to draw liquid or air into the stream; normally used to draw regeneration chemicals into an ion exchange water treatment system, like deionizer or softener.

35 Comments

  1. I WANT MORE & more gk fully deeply

  2. Chitta Ranjan Barik says:

    I am chitta Ranjan Barik… Good job plumbing

  3. Onesimo HolweniOn says:

    Im nevourse tomorrow ihave interview for plumbing aprentice but i learn more here thank you

    1. hey just curious on what they ask you for the interview?

    2. yeah it’s okay the only thing have todo is before the interview be confidence in every line of the interviewer asking questions

  4. Alexander mufimba says:

    IAM an upcoming plumber am for this refresher course thank you so much.

  5. Alexander mufimba says:

    IAM a plumber am very happpyfor this refresher course thank you so much.

  6. lamberta706 says:

    Thanks for posting this amazing Article with us. Nicely explain the plumbers interview questions & their answer. I know, very important things over here. Keep posting and keep sharing like this.

  7. Vijay Kumar says:

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  8. Wapinga aggrey says:

    Surely it is coordinative

  9. Asivina learo says:

    Thanks very much for questions and answers

  10. Asivina learo says:

    Thanks very much for questions and answers I have learn alot

  11. Nkosi Vumile Njebo says:

    I like to thank you for this question and answers

  12. Mohamed Papa Bangura says:

    It is very touch full plumbing question and answers i Lear learn a lot from it

  13. I have a written test on 19th this month. I hope this will make me a successful candidate

  14. Symon Mkonda says:

    Very understandable i like iit

  15. Phenicance Kayegga says:

    I have appreciated all efforts taken to enlighten plumbers and public for healthy and safety measures. Keep it up dear. Sincerely, Phenicance Kayegga, The Master & Consultant Plumber in Uganda, East Africa

  16. Darshan Bhati says:

    Very good questions

  17. Gurpreet Singh Kharal says:

    Hi. I have interview after 10 days . I am bit nervous. Anyone can help me for preparation or providing me some data related to plumbing for qualifying the skill assessment in phase ii in plumbing ( interview phase). Thanks

  18. Ra's sangosah says:

    I,have an interview for plumbing foreman in a company.happy to Read this!!!

  19. James M House says:

    Wow thanks for sharing this awesome info with us enjoyed every bit of it.

  20. Drani Albert says:

    It is very good guestions i learn

  21. Vivekananda mohanty says:

    First time I’ve to face interview to going gulf country in plumbing maintenance, so give me some questions and answer

  22. AnilKumarPradhan says:

    I am Plumber Lookigi Job

    1. Charles Hiine says:

      I am plamber Im looking job

  23. NUHU DAVID NYAMBULAPI says:

    very nice its a very active and target able question

  24. Anaatolia Simon says:

    Iam plumber . I need to learn more

  25. Charles mageto says:

    I have gained something

  26. Jujhar singh says:

    Please provide three or more skills that make you a good fit for this position.(i need answer this one)

  27. Charles Hiine says:

    I am plamber Im looking job

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