Do Plumbers Install Boilers? What You Really Need to Know

When your boiler breaks down in the middle of a Toronto winter, you don’t have time to figure out who to call. You just want heat. So you grab your phone and dial the first plumber you can find. But here’s the question that’s been buzzing in your head: Do plumbers install boilers? The answer isn’t as simple as yes or no-and getting it wrong could cost you time, money, or even your safety.

Plumbers and boilers: a messy overlap

Plumbers are experts in water. They fix leaks, install pipes, connect sinks and showers, and make sure your home’s water flows where it should. Boilers, on the other hand, are heating systems that use water-or sometimes steam-to warm your house. So yes, plumbers work with water in boilers. But that’s like saying a car mechanic can install an airplane engine because both have wheels.

Most boilers are gas-fired. That means they burn natural gas to heat water. Gas lines, ventilation, combustion chambers, pressure systems, thermostats-these aren’t plumbing tasks. They’re heating system tasks. In Ontario, only technicians certified by the Technical Standards and Safety Authority (TSSA) can legally work on gas appliances. That’s not just a recommendation. It’s the law.

So while a plumber might know how to connect the cold water feed to a boiler, they likely don’t know how to check the flue gas composition, test for carbon monoxide leaks, or adjust the burner flame. And if they try? You’re risking a dangerous situation.

Who actually installs boilers?

The right person to call is a gas boiler installer-often called a heating technician or HVAC specialist. These professionals are trained specifically for boilers. They understand the difference between a condensing and non-condensing unit. They know how to size a boiler correctly for your home’s square footage and insulation levels. They can read pressure gauges, test safety valves, and connect the system to your existing radiators or underfloor heating.

In Ontario, a licensed gas fitter (Level 2 or higher) is required to install or service gas-fired boilers. These technicians go through hundreds of hours of training, pass written and practical exams, and are regularly audited by TSSA. Many also hold additional certifications from manufacturers like Worcester Bosch, Vaillant, or Buderus.

You might see a plumber advertising boiler installation. That doesn’t mean they’re qualified. Some plumbers partner with gas fitters or hire them as subcontractors. Others have taken a weekend course and call themselves "boiler specialists." But if they’re not TSSA-certified for gas work, they’re breaking the law-and putting you at risk.

Why the confusion exists

The confusion comes from history. In the past, plumbers often handled everything related to home heating. Older homes had simple steam boilers connected to radiators, and the plumbing and heating systems were more intertwined. But modern boilers? They’re complex machines. They have electronic controls, modulating burners, smart thermostats, and integrated safety sensors. They’re not just water tanks with a flame underneath.

Plus, many homeowners don’t know the difference between plumbing and heating. If your radiator leaks, you call a plumber. If your boiler stops working, you assume the same person can fix it. But leaking radiators? That’s plumbing. A boiler that won’t ignite? That’s gas system repair.

Even the term "plumber" is used loosely. Some companies call their heating technicians "plumbers" because it’s easier for customers to remember. But don’t let the name fool you. Always ask: "Are you TSSA-certified for gas boiler installation?" If they hesitate, walk away.

What happens if you hire the wrong person

Hiring someone without proper gas certification can lead to serious consequences:

• Carbon monoxide poisoning-a silent, odorless gas that can kill. Improper venting or burner tuning is a leading cause.
• Gas leaks-a single loose fitting can fill your home with flammable gas. One spark, and it’s over.
• Voided warranties-manufacturers require installation by certified technicians. If you don’t have proof, your warranty is worthless.
• Insurance denial-if a fire starts because of improper boiler installation, your home insurance may refuse to pay.
• Fines-TSSA can fine homeowners for unlicensed gas work, even if you didn’t do it yourself.

I’ve seen cases where homeowners saved $500 by hiring a handyman instead of a certified tech. Three months later, the boiler failed, the house was cold, and the repair bill was $3,200. Plus, they had to pay for a TSSA inspection to make everything legal again.

What to look for when hiring

Don’t just pick the cheapest quote. Here’s what to ask:

1. "Are you TSSA-certified for gas boiler installations?" (Ask for their license number and verify it at tssa.org.)
2. "Do you carry liability insurance for gas work?"
3. "Will you provide a gas safety certificate after installation?"
4. "Which boiler brands do you install and service?"
5. "Can you show me proof of manufacturer training?"

A reputable installer will hand you a copy of the TSSA gas safety certificate right after the job. It includes the serial number of the boiler, the date of installation, and their license number. Keep it with your home documents.

When a plumber might help

There are times when a plumber is useful alongside a boiler installer:

• Replacing copper pipes leading to the boiler
• Installing a new water pressure relief valve
• Connecting the boiler to a new hot water tank
• Fixing a leaky radiator connection

But here’s the rule: if the job involves the gas line, the burner, the control board, or the flue-leave it to the gas fitter. The plumber can handle the water side, but only after the gas side is safely installed and inspected.

Boiler replacement in Toronto: what to expect

A typical boiler replacement in a Toronto home takes 1-2 days. The old unit is removed, the gas line is tested for leaks, the new boiler is mounted, connected to water and gas, programmed, and tested. The technician will run a combustion analysis to ensure it’s burning cleanly. They’ll also check your radiators and system pressure.

You’ll pay between $4,500 and $8,500 for a mid-range gas boiler with professional installation. That includes the unit, labor, permits, and the TSSA inspection. Cheaper options usually mean lower-quality parts or unlicensed labor. Don’t be tempted.

What about electric boilers?

Electric boilers are different. They don’t use gas, so TSSA certification isn’t required. But they still need to be wired properly and connected to your home’s electrical system. That’s where a licensed electrician comes in. Some plumbers are also licensed electricians, but that’s rare. Most electric boilers are installed by HVAC technicians who specialize in electric systems.

Bottom line: Don’t guess. Verify.

Plumbers don’t install boilers-not legally, not safely, not reliably. What they do is handle the water side of the system. The boiler itself? That’s the job of a certified gas technician.

If your boiler fails, don’t panic. Call a TSSA-certified gas fitter. Ask for proof of certification. Get a written quote. Check reviews. Don’t settle for someone who says, "I’ve done this before." In heating, "before" doesn’t mean qualified. It just means lucky.

Your home and your family’s safety aren’t worth risking on a guess. When it comes to boilers, trust the license-not the title.