At a glance
- 01
Certified gas technicians
Requests go only to contractors whose technicians hold a TSSA gas certificate, which Ontario requires for any work on a gas furnace.
- 02
No-heat calls first
Mark the request as an emergency and it goes to a contractor who takes same-day and after-hours calls.
- 03
Repair or replace, honestly
Ask for the repair price and the age-based case for replacement side by side. A good technician gives you both.
- 04
One request, one call back
Your details go to one contractor who works your area, not a list of companies.
What usually goes wrong with a furnace
Most furnace repair in Hamilton comes down to a short list of parts. A modern high-efficiency gas furnace runs through the same sequence every time the thermostat calls: the inducer fan starts to clear the venting, a pressure switch confirms the draft, the hot-surface igniter glows, the gas valve opens, the flame sensor proves there is flame, and after a short delay the blower pushes warm air through the house. If any step fails, the control board shuts the burner down and usually flashes a code through the little window on the door.
That design is why a furnace that stops in January is often a cheap fix. A dirty flame sensor, a cracked igniter, a blocked condensate drain or a clogged filter cause a large share of no-heat calls, and none of them means the furnace is finished.
- Flame sensor: a thin rod that gets coated over time. The burners light, then shut off after a few seconds.
- Igniter: hot-surface igniters crack with age. You hear the inducer, but the burners never light.
- Condensate drain or trap: high-efficiency furnaces make water. A blocked trap trips a safety switch, and the furnace refuses to run.
- Pressure switch or inducer motor: a failing inducer hums, rattles or will not prove draft.
- Blower motor or capacitor: the burners run but little or no air comes out of the vents.
- Control board: the brain of the furnace, sometimes damaged by power surges or a failing part elsewhere.
Check these before you call
A few things are worth a minute before you book anyone. Make sure the thermostat is set to heat and has fresh batteries. Check that the furnace switch, which looks like a light switch on the wall or the side of the unit, is on, and that the breaker has not tripped. Pull the filter: a filter caked grey can make the furnace overheat and shut itself off. On a high-efficiency furnace, look outside at the two white plastic pipes and make sure snow or ice is not blocking them. Our furnace not working checklist goes through each step and what the blinking codes usually mean.
Do not reset the furnace over and over, and do not take panels off the burner side. If you smell gas, leave the house and call Enbridge Gas at 1-866-763-5427 or 911 from outside.
Who is allowed to repair a gas furnace
In Ontario, work on gas appliances is regulated by the Technical Standards and Safety Authority (TSSA). A technician needs a gas technician certificate, usually a G2 for residential furnaces, and the company needs to be a TSSA-registered contractor. The same applies to propane furnaces, and oil furnaces need a certified oil burner technician. It is fair to ask for a certificate number. Every contractor we refer to holds the certificates the job needs.
Repair or replace?
A furnace usually lasts 15 to 20 years, and the guide on how long a furnace lasts explains what shortens that. As a rough rule, if the furnace is past 15 years and the repair costs more than a third of a new one, replacement starts to make more sense. A cracked heat exchanger on an older unit almost always means replacement: it can let combustion gases, including carbon monoxide, into the air you breathe, and a technician who finds one will shut the gas off to the furnace.
Other signs point the same way: repeated breakdowns in the last two winters, rooms that never warm up, a furnace that is a mid-efficiency model from the 1990s, or a plan to add a heat pump anyway. If replacement is on the table, a new furnace installation quote and the new furnace cost guide help you compare.
Carbon monoxide
Ontario law requires a working carbon monoxide alarm next to every sleeping area in a home with a fuel-burning appliance, a fireplace or an attached garage. If a CO alarm goes off, get everyone outside and call 911. A furnace that has been producing CO needs to be checked by a certified technician before it runs again.
What the visit looks like
- The technician asks what happened and reads any fault code on the control board.
- They run the furnace through its start-up sequence and test each safety device in turn.
- They check the gas pressure, the flame, the venting and the temperature rise across the furnace.
- They quote the repair before doing it, and say whether the furnace is safe to run in the meantime.
- After the fix, they run a full cycle and check the heat exchanger and venting while the panels are off.
How the request works
HVAC in Hamilton does not send out technicians. You request a furnace repair once, and we pass it to one licensed contractor who works your area, whether that is the lower city, Burlington or Haldimand County. They call you, confirm what is happening and book the visit. Say on the form if the heat is out, if anyone in the house is elderly or unwell, or if pipes are at risk, so the contractor can put you ahead of routine work.
Typical prices
CAD · before GST/HST
- Diagnostic service callOften credited against the repair
- $120–$200
- Flame sensor clean or igniter replacement
- $150–$450
- Inducer motor, pressure switch or control board
- $450–$1,200
- Blower motor replacementVariable-speed (ECM) motors at the top end
- $700–$1,500
- After-hours or holiday surcharge
- $100–$250
Typical 2026 installed prices in Hamilton and the surrounding area, before HST and before any rebate. They are a guide, not a quote: the contractor you are matched with sets the price after seeing the home.
Questions people ask
How much does furnace repair cost in Hamilton?
Most repairs land between $150 and $1,200 before HST, plus a service call of $120 to $200 that many contractors credit against the work. Flame sensors and igniters sit at the low end; inducer motors, control boards and blower motors at the high end.
Why does my furnace start and then shut off after a few seconds?
The most common cause is a dirty flame sensor: the furnace lights, cannot prove the flame, and shuts the gas off for safety. A blocked vent or condensate drain can do the same. A technician can clean or test each one in a short visit.
Is it safe to run a furnace that is making a strange noise?
A squeal or rattle from the blower is usually mechanical and not dangerous in the short term. A loud bang on ignition, a burning smell that lasts, or any gas smell is different: shut the furnace off and have it checked first.
Do you handle propane and oil furnaces?
Yes. Rural homes in Haldimand, Norfolk and parts of Flamborough often run on propane or oil. We pass those requests to contractors with the right TSSA certificates for that fuel.
Can a furnace be repaired the same day?
Often, if the part is common and on the truck: igniters, flame sensors, capacitors and pressure switches usually are. Control boards and motors for less common models can take a day or two to arrive.