A lot of the no-heat calls we get in winter turn out to be something simple: a thermostat battery, a tripped switch or a clogged filter. Before you book a service call, run through these seven safe checks. If none of them fixes it, call us and you’ll at least be able to tell us what you’ve ruled out.
Safety first. If you smell gas (rotten eggs), don’t touch any switches. Leave the house and call FortisBC’s 24-hour emergency line at 1-800-663-9911 from outside. If your CO alarm is going off, get everyone out and call 911.
1. Check the thermostat
- Is it set to Heat, not Cool or Off?
- Is the set temperature higher than the room temperature?
- Is the screen blank? Replace the batteries (usually AA or AAA).
- Smart thermostat? Check that it hasn’t gone into an away or eco schedule.
2. Check the furnace switch
There’s a light-switch-style power switch on or near the furnace, often at the top of the stairs to the basement or on the side of the unit. People flip it off by mistake all the time. Make sure it’s on.
3. Check the breaker
Find the furnace breaker in your electrical panel. If it’s tripped, reset it once. If it trips again, stop and call us. Something is drawing too much power.
4. Check the filter
A clogged filter is the most common cause of a furnace that runs for a few minutes and shuts off. The furnace overheats and a safety switch shuts it down. Pull out the filter. If you can’t see light through it, replace it. Most homes here need a new filter every 1–3 months in winter.
5. Check the front panel
The blower door has a safety switch. If the panel isn’t seated properly, the furnace won’t run. Push it firmly into place.
6. Check the vent pipes outside
High-efficiency furnaces vent through two white PVC pipes on an outside wall. In a snowfall, especially in Cloverdale, Langley and up on the plateaus, snow or ice can block them, and the furnace shuts itself off. Clear snow away carefully by hand.
7. Look at the status light
Most modern furnaces have a small window with a flashing LED. Count the flashes and check the chart on the inside of the panel door. Even if you can’t fix the fault, telling us the code (“3 flashes”) helps us bring the right part.
When to stop and call a professional
- You smell gas or your CO alarm sounds (leave the house first).
- The breaker trips again.
- You hear banging, screeching or grinding.
- The furnace starts, then shuts off over and over after a new filter.
- You see water pooling under the furnace.
- You see soot or scorch marks around the burner area.
Don’t try to relight burners, bypass safety switches or open the gas valve. In BC, gas appliance work must be done by a licensed gas fitter. It’s also the law.
What a furnace repair usually costs
A diagnostic visit in Surrey is typically $129–$179. Common repairs such as an igniter, flame sensor or pressure switch usually run $200–$600 including the visit. A blower motor or control board costs more. See our furnace repair page for details.
Repair or replace?
If your furnace is 15 or more years old and the repair is more than about a third of the cost of a new one, it’s worth getting a replacement quote too. With rebates, a dual fuel heat pump may cost not much more than a new furnace alone.
FAQ
Why does my furnace blow cold air? It’s often a dirty flame sensor, a clogged filter or a thermostat set to “Fan On”.
How cold can my house get before pipes freeze? Keep it above about 12°C. Open cabinet doors under sinks on outside walls.
Can I use space heaters while I wait? Yes, but keep them well away from curtains and bedding, and never use a gas BBQ or camp heater indoors.
No heat? We'll come out
We work across Surrey, Langley, Delta and White Rock, and we answer the phone. Call 778-903-2414 or request a repair.
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