Is your furnace turning on and off unexpectedly? Short cycling, as the pros call it, is a frustrating and all-too-common occurrence. Generally speaking, there are four major causes for this problem that you should know and be able to identify.

Is Your Furnace Filter Clogged?

This is one of the most common causes of HVAC short cycling. As its name suggests, the air filter cleans the forced air that flows into your home from the HVAC system. However, over time, the debris a filter collects can restrict the airflow in your system. When this happens, your HVAC system overheats, which prompts it to shut down prematurely. To prevent this issue, wash or replace your air filters at least every month to ensure that there is no debris buildup.

Is Your Thermostat in Good Working Condition?

The thermostat serves as the brain of your HVAC system by dictating the indoor temperature it should maintain. A malfunctioning thermostat will tell your unit that the desired temperature has already been reached and that it should therefore shut down. To make sure, however, replace your thermostat’s batteries and then turn it off and on. Let your furnace run for about an hour to see if the thermostat is communicating the temperature accurately to your furnace.

One last thing: Check where your thermostat is located—factors such as exposure to direct sunlight or being close to a space heater can trip up its readings.

Are Your Windows Allowing Warm Air to Escape?

Another place you should check is your windows. Are there gaps in them where warm air is escaping? Poor insulation can cause a furnace to work overtime, which in turn can potentially cause short cycles. If you see that the seals around your windows have been compromised, you can apply caulk to address the problem. Likewise, make sure that all windows and doors are closed to improve your home’s insulation and make life easier for your furnace.

Is the Burn Sensor Corroded?
As one of the most crucial parts of your furnace, the burn sensor detects whether the flame is on. If your system is powered but the flame is not detectable, your HVAC will automatically shut down as a precautionary measure. However, locating and diagnosing issues for the burn sensor can be tricky, especially as different models locate it in different places. To be safe, be sure to call an Edmonton furnace service expert.

A furnace is a complex appliance, and understanding the common causes of short cycling will help you better diagnose this problem. Of course, when you do spot the problem, don’t hesitate to request professional servicing to address the issue.