Who installs water heaters: plumber, gasfitter, HVAC technician or electrician?

01 /Is a water heater plumbing or HVAC?

Both, and the useful question is which connections the job touches. A water heater joins three regulated systems: the drinking-water piping, the fuel supply with its venting, and for many models the electrical system. Each is licensed separately, so the right installer is whoever holds credentials for every connection your job changes.

That is why the same job gets quoted by different kinds of company. Plumbing firms often employ gas-certified staff, and heating and cooling (HVAC) firms often hold gas contractor credentials because furnaces and water heaters share the same fuel and venting rules. What matters is whether the person at your tank holds the certificate for the work they are touching.

02 /Who may legally connect gas, water and electricity?

In broad terms across Canada, gas work is restricted to certified individuals working under a licensed or registered gas contractor; plumbing is a regulated trade, with homeowner exceptions that vary by province and municipality; and electrical work done for you by someone else needs an appropriately licensed electrician or contractor in the provinces checked here. Permits and inspections sit on top of the licensing: an authority issues a permit for the work and then inspects it.

The provincial sections below were checked on official sites in September 2026. Rules change, so confirm with the authority named before work starts. How permits work in general is covered in water heater permits and code.

03 /How does water heater licensing work in Alberta?

• Compulsory trades. The Government of Alberta lists Plumber, Gasfitter – Class A, Gasfitter – Class B and Electrician as compulsory certification trades. To perform their restricted activities, a person must be a registered apprentice working under a certified journeyperson, a certified journeyperson, or hold a recognized trade certificate.
• Gas scope. The province's Gasfitter – Class B profile describes the trade as sizing, installing, testing, adjusting and servicing natural gas and propane equipment ranging from residential furnaces to industrial boilers of up to 400,000 BTUs, a range that takes in household water heaters.
• Checking a person. The Tradesecrets tradesperson lookup shows whether someone holds an Alberta journeyperson certificate or is a registered apprentice, and in which trade. You need their first and last name and their certificate or ID number, and it cannot search credentials issued outside Alberta.
• Checking a company that takes deposits. Businesses that negotiate or sign contracts in person away from their own premises and take money before the work is finished must hold a prepaid contracting licence; Service Alberta's Find a Licensed Business search confirms it.
• Permits. Gas, plumbing and electrical permits are issued locally. Calgary's limits on homeowner gas permits are summarized in permits and code; elsewhere, ask your municipality.

04 /How does water heater licensing work in British Columbia?

• Gas contractors. Technical Safety BC says that to perform regulated gas work you must be licensed by it, be employed by a contractor it licenses, or be authorized to do the work yourself, as with a homeowner gas permit. Licensed contractors must take out the permit and file a notification of completion when the job is done.
• Gas certificates. Individuals hold certificates by type, including Class A and Class B gas fitter, gas appliance service technician, gas venting and gas piping.
• Compulsory trades. Under B.C.'s Skilled Trades Certification, designated trades including Gasfitter Class A and Class B, construction electrician, refrigeration and air conditioning mechanic, steamfitter/pipefitter and sheet metal worker must be done by registered apprentices, certified journeypersons or workers on an approved pathway.
• Checking. Technical Safety BC's Find a Licensed Contractor registry shows whether a company is currently licensed for gas work. Ask your municipality how plumbing permits are handled where you live.

B.C. is also the main province with a homeowner gas permit route for water heaters, with eligibility rules and a required inspection; can I replace my own water heater covers who qualifies.

05 /How does water heater licensing work in Ontario?

• Gas contractors. The Technical Standards and Safety Authority (TSSA) states that registered fuels contractors are the only businesses legally authorized to do fuels-related work in Ontario. Its public registry can be searched by company name, authorization number or location, and registration numbers take the form FS-R- followed by digits.
• Gas technicians. Individuals are certified under Ontario Regulation 215/01 in categories that include gas technician 3, 2 and 1 and gas piping fitter, and TSSA's policies oblige each holder to work only within the scope of their certificate. Ask which certificate the technician at your tank holds.
• Plumbers and electricians. Skilled Trades Ontario lists plumber and electrician among the province's compulsory trades. Anyone working in them must hold a certificate of qualification, a provisional certificate of qualification or a registered training agreement, and the Skilled Trades Ontario Public Register confirms it.
• Electrical contractors. The Electrical Safety Authority tells homeowners to hire a Licensed Electrical Contractor, ask for the ECRA/ESA licence number and verify it with ESA's Find a Contractor tool. The contractor files the notification of work, and a Certificate of Acceptance follows.
• Plumbing permits come from your municipality's building department.

06 /How does water heater licensing work in Quebec?

• Contractor licence. Plumbing work in Quebec needs the appropriate contractor or owner-builder licence from the Régie du bâtiment du Québec (RBQ). For plumbing and heating, the Corporation des maîtres mécaniciens en tuyauterie du Québec (CMMTQ) acts as the RBQ's mandatary and decides licence applications.
• Gas. The CMMTQ states that all work on a gas installation or a gas-fired appliance must be given to a specialized contractor who is a CMMTQ member.
• Owner exception. In a single-family house the owner lives in or intends to live in, used only to house them or their family with no business, extra dwelling or income, an individual may do their own plumbing and heating work without a licence, except gas and oil work. They must still declare the work to the RBQ and meet the codes in force. Work given to anyone else must go to a CMMTQ member holding the appropriate licence.
• Electrical. Electrical installation work needs a licence carrying subclass 16, and the Corporation des maîtres électriciens du Québec (CMEQ) qualifies electrical contractors on the government's behalf. A new circuit for an electric or heat pump water heater falls here.
• Checking. Enter the contractor's licence number in the RBQ's licence holders' repertory. The RBQ notes that hiring a licensed contractor gives you financial protection if a dispute ends in litigation. For individual workers, ask to see their competency certificate.

07 /What about the other provinces and territories?

Broadly the same structure applies elsewhere: a safety regulator that certifies gas fitters and licenses or registers gas contractors, a plumbing trade with permits issued locally, and electrical permits from a provincial or municipal authority. Names, fees and homeowner exceptions differ, so treat this page as the pattern and confirm with your province's safety authority or your municipality. The Ontario guide and the other province guides, such as Alberta, British Columbia and Quebec, add local detail, and Across Canada compares regions.

08 /Why is homeowner gas work restricted?

Because the failures are invisible and can kill. A gas joint that seeps, a vent connector that slopes the wrong way or a burner short of combustion air can cause a leak, a fire or carbon monoxide spillage without any sign on the day the job is finished. Certification means the person has been trained and tested on the gas code, and the permit means a second person checks the work.

• Testing needs instruments. Leak testing, draft checks and combustion analysis need tools and training most owners do not have.
• Venting is code-heavy. Vent sizing, slope, clearances and termination locations come from CSA B149.1 as adopted by each province; see venting and backdraft.
• Insurance and warranty. Unpermitted gas work can complicate an insurance claim, and many heater warranties call for a qualified installer.
• Even restoring gas is restricted. PreparedBC advises that if gas is shut off at the meter, you should not turn it back on yourself; a licensed gas contractor should.

09 /What should you ask a water heater contractor before hiring?

1. Which licences cover this job?

   Ask for the company's gas contractor licence or registration number, plus its plumbing and electrical licences where your province requires them, and write them down.

2. Who will do the work?

   Ask which certificate the technician holds, whether an apprentice will work under supervision, and whether any part, such as a new circuit, is subcontracted.

3. Who pulls the permit?

   The contractor doing the gas work should take out the permit and book the inspection. Ask whether the fee is in the price.

4. What is included?

   Venting, expansion tank, T&P discharge pipe, drain pan, disposal, and return of a rented tank. The installation guide has the full checklist.

5. What insurance and warranty come with it?

   Ask about liability insurance and the labour warranty, and get both in writing.

6. How much is due up front?

   A deposit is normal; a large prepayment to an unlicensed business is a warning sign. In Alberta, check the prepaid contracting licence.

Once you know who is qualified, you can request quotes and compare them on the same scope. If you are also deciding what to install, the Hot Water Morning Simulator shows whether a given heater keeps up with your busiest morning, which is worth settling before an installer suggests a size.

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