Furnace Not Working on a Cold Alberta Night? 6 Things to Check Before You Call
It is 10 at night, it is well below freezing outside, and your furnace has gone quiet. Before you panic, take a breath.
A surprising number of no heat calls come down to a few simple things you can safely check yourself in a couple of minutes. Below are six of them, in the order worth trying, plus the warning signs that mean you should stop and call a professional right away.
The 6 things to check
- 1
Start at the thermostat
It sounds obvious, but this is the most common fix. Make sure it is set to HEAT, that the temperature is set a few degrees above the current room temperature, and that the fan is on AUTO rather than ON. If your thermostat runs on batteries, a dead battery can shut everything down, so try fresh ones.
- 2
Check the power and the breaker
Your furnace has an on and off switch nearby that looks like a regular light switch, and it sometimes gets flipped by accident. Make sure it is on. Then check your electrical panel for a tripped breaker labelled for the furnace. If a breaker keeps tripping after you reset it once, stop and call a pro, because that points to a deeper issue.
- 3
Look at the furnace filter
A filter clogged with dust and pet hair chokes the airflow and can cause the furnace to overheat and shut itself off as a safety measure. If your filter looks grey and packed, replace it with a new one of the same size. In our long heating season, filters fill up faster than people expect.
- 4
Make sure the front panel is fully closed
Most furnaces have a safety switch that will not let the unit run unless the front access panel is properly seated. If someone recently changed the filter, the panel may not be clicked fully back into place.
- 5
Check the outside intake and exhaust pipes
This one is specific to our winters. High efficiency furnaces vent through plastic pipes that exit the side of your house, and in heavy snow or a deep freeze these can get blocked by drifting snow, ice, or frost. A blocked intake or exhaust will safely shut the furnace down. If you can safely reach the vents outside, gently clear away any snow or ice around them. Never force anything into the pipes.
- 6
Try the reset once, and only once
Some furnaces have a reset button. Turn the furnace off at the thermostat, wait about 30 seconds, then press the reset button one time. If the furnace fires up and stays running, great. If it does not start, or it starts and quickly shuts off again, do not keep pressing it. Repeated resets can be unsafe and usually mean the furnace needs a technician.
When to stop and call a professional
Some situations are not DIY. Call a licensed technician right away if you notice any of these.
- Any smell of gas, or a carbon monoxide alarm sounding (get out first, then call)
- The furnace starts and then shuts off again in a short cycle
- You see the igniter glow or hear it click but no flame or heat follows
- A breaker that trips again after you reset it once
- Soot, a strong burning smell, or visible water pooling around the unit
- It simply will not start after the checks above
There is no prize for pushing a furnace that is trying to protect you. When in doubt, make the call.
We are here when the heat goes out
When it is -30 and the furnace quits, waiting until morning is not an option for most families. City Furnace Mechanical has served the greater Edmonton area since 2003, and we offer 24/7 emergency service for exactly these nights. Our licensed journeyman technicians carry common parts, work on all makes and models, and will talk you through the situation honestly before anyone comes out.
People also ask
Why is my furnace not turning on during extreme cold?
Deep cold can freeze the outside intake or exhaust vents, which safely shuts the furnace down. Filters, thermostats, and tripped breakers are also common causes. Clearing snow from the outside vents and checking the thermostat and breaker solves many cases, but if it will not restart, call a professional.
Is it safe to hit the reset button on a furnace?
Pressing the reset once is generally fine. If the furnace does not start or shuts off again, do not keep pressing it. Repeated resets can be unsafe and usually mean the unit needs a technician.
How can I tell if my furnace might be producing carbon monoxide?
Carbon monoxide is odourless, so a working CO alarm is essential. Warning signs can include soot around the furnace, a yellow rather than blue burner flame, and feeling unwell or drowsy indoors. If your CO alarm sounds, get everyone to fresh air and call for help immediately.
How often should I change my furnace filter in winter?
A common guideline is every one to three months, but during our long heating season and with pets, checking monthly is smart. A clogged filter is one of the most common reasons a furnace overheats and shuts down.
Do you offer emergency furnace repair in the greater Edmonton area?
Yes. We offer 24/7 emergency service and do our best to fit urgent no heat calls into the same day, especially through winter.