Every January, our call volume in Oshawa spikes the same way: a cold snap hits, temperatures drop below -15°C for a few days straight, and furnaces that had been quietly limping along all fall finally give out. It’s not a coincidence. Extended cold snaps put more strain on a furnace than any other time of year, and small problems that go unnoticed in October become full breakdowns in January.
Why the Cold Snap Is the Trigger
A furnace that runs for 10 minutes at a time in the fall might run for hours without stopping during a deep freeze. That extra runtime means:
- More wear on the blower motor — bearings and belts that were already worn accelerate toward failure.
- Higher strain on the heat exchanger — repeated heating and cooling cycles can widen existing cracks.
- Increased load on the ignition system — igniters and pilot assemblies that were marginal often fail under constant cycling.
- More demand on old thermostats — battery and wiring issues that were tolerable become no-heat situations.
What This Means for Oshawa Homeowners
If your furnace is more than 12–15 years old, or if you’ve noticed short cycling, strange noises, or a pilot light that won’t stay lit, don’t wait for the next cold snap to deal with it. A fall inspection catches most of these issues before they turn into a 2 AM no-heat call.
What to Do Now
- Book a fall tune-up before the first hard freeze.
- Replace your furnace filter — a clogged filter is one of the most common (and cheapest to fix) causes of a mid-winter breakdown.
- Test your thermostat, including battery backups if it has them.
- Know who you’ll call if the furnace does go down. A 60-minute response matters a lot more at -20°C than it does in October.
If your furnace stops working during a cold snap, don’t wait it out — call our dispatcher and a technician will be on the road within the hour.