Losing heat is stressful whether you’re in a house or a condo, but what you check first is different depending on which one you’re in. Work through the section that matches your situation.
If You’re in a House
- Thermostat — is it set to Heat, and is the target temperature above the current room reading? Check batteries if it’s battery-powered.
- Breaker panel — has a breaker tripped for the furnace circuit?
- Furnace switch — many furnaces have a wall switch near the unit that looks like an ordinary light switch. It’s easy for this to get bumped off in a basement.
- Filter — a badly clogged filter can cause the furnace to shut itself down as a safety measure. If it’s visibly packed with dust, swap it and see if the system restarts.
If You’re in a Condo
- Confirm it’s not a building-wide issue first. Check with a neighbour or the building’s resident portal — if the whole building has no heat, that’s a management issue, not something an in-suite call will fix.
- Check your fan coil’s own thermostat and filter. Even when the building’s system is running fine, a clogged in-suite filter or a tripped breaker for your unit specifically can leave you with no heat while everyone else is fine.
- Look for a leak near the unit. A blocked condensate line can trigger a safety shutoff on some fan coil units.
Look for an Error Code
Many furnaces and some fan coil units display a blinking light code. Photograph the pattern before you call — it tells a technician what fault the system is reporting, which speeds up the visit.
What Not to Do
Don’t take apart the unit, don’t reset it repeatedly hoping it “catches,” and don’t touch anything related to gas lines or ignition yourself. Gas components are legally restricted to TSSA-licensed technicians in Ontario, and repeated resets on a genuine fault can make things worse.
When to Call
If you’ve ruled out a building-wide issue (for condos) or worked through the basics (for houses) and it still won’t run — or you smell gas at any point — stop troubleshooting and call immediately. That’s especially true with young kids, older family members, or pets in the home.
Our dispatcher answers 24/7, and a technician can typically be on-site within 60 minutes anywhere in Mississauga.