Why did my heat shut off in the middle of the night?
Heat failing overnight is rarely a coincidence — it's usually the coldest hours exposing a fault that daytime temperatures hid. Frozen intake or exhaust vents, a heat pump whose backup heat never engaged, and safety switches tripping under sustained load are the usual causes, and in a New Brunswick winter this becomes a frozen-pipe risk rather than just a comfort problem.
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What you can safely check
- Check the outside vents first
- On a high-efficiency furnace, snow drift or an ice cap over the intake or exhaust pipe will stop it overnight. Clear it by hand.
- Thermostat and breaker
- Batteries, then reset the breaker once.
- Protect the plumbing
- If the house is dropping toward freezing, open the cupboard doors under sinks on exterior walls and run a pencil-thin trickle from the furthest tap.
- Heat pump owners — check backup heat
- Set the thermostat to emergency heat. If that warms the house, the pump has failed but you have heat tonight.
What’s probably going on
- Frozen vent
- The most common overnight failure here, and the one most often fixed with a broom.
- Heat pump below its balance point
- At the coldest hour it needs supplementary heat. If the backup failed, the house quietly loses ground.
- Tripped safety under sustained running
- Faults that never surface on a mild day appear when the system runs for hours without a break.
Stop here and call
If the house is below about 13°C and still falling, treat it as urgent — call the emergency line rather than waiting for business hours. Frozen pipes cost far more than an after-hours call.
What we do about it
We answer after hours. Call (506) 472-9954 — if we can't reach you tonight we'll tell you that straight, and tell you how to protect the plumbing until we can.
Still stuck?
Tell us what the system is doing and we’ll tell you what it takes to fix — free quotes, no obligation, and a straight answer about whether it’s worth repairing.