When a high-efficiency gas furnace stops working in the middle of a London, Ontario winter, it can quickly become an urgent situation. Before calling for service, there are a few safe and simple things homeowners can check. These steps may help restore heat, or at least narrow down the issue for our technician.
1. Check Your Thermostat
- Is it set to 'Heat'?
- Is it set above the current indoor temperature?
- Is it powered on (it may need new batteries)
2. Confirm the Furnace Has Power
- Gas Furnaces require power to operate.
-
Check to see if the furnace power switch is on.
(It's normally in the same room as your furnace) -
Check the circuit breaker on your electrical panel
(If you reset the breaker and it continues to trip, you will need to call us)
3. Check the Furnace Filter
- A dirty filter can restrict air flow and cause the unit to shut down.
- Remove your furnace filter and inspect it.
- Replace the filter if it's dirty or you cannot remember when it was last replaced.
4. Check the Condensate Drain Line
- High-efficiency gas furnaces produce condensation that must drain properly.
- Can you tell if the drain line is kinked or plugged?
- Is there water pooling near the furnace?
5. Is your natural gas supply working?
- Are your other gas appliances (water heater, stove, fireplace) working?
6. Inspect the Intake and Exhaust Vent Pipes
- Snow, ice or leaves can block these pipes and cause the furnace to shut down.
- Clear snow or ice away from these pipes.
- This is a very common issue during London’s winter storms.
7. Try a Basic Furnace Reset
- After you have checked all the above items, try turning the furnace off at the switch, waiting about one minute, and turning it back on.
- If the furnace shuts down again, do not continue resetting it.
