Why is Your Gas Furnace Overactive and Cycling On and Off Frequently?

Man fixing gas furnaceShort cycling is an error or malfunction that could cause your gas furnace to cycle between turning on and off for brief amounts of time, typically around four to eight seconds.

If your gas furnace is displaying this behavior, it’s most probably short cycling. Many different things, with the following being the most common, could cause short cycling:

Filthy Air Filters

These could cause backups and restrict airflow, causing the blocked air to stay inside the furnace and boost internal temperature. This, in turn, leads to the furnace being turned off. Due to the warm air not seeping into your home, the temperature stays low and results in additional furnace cycles. Furnace repair specialists in Utah and other states suggest checking your air filters to see if you could still clean them or if they need replacement as soon as possible.

Malfunctioning Thermostat

An improperly positioned or damaged thermostat could result in short cycling. Avoid positioning your thermostat in direct sunlight or close to heat sources to prevent it from getting warmed up, therefore signaling your gas furnace to turn off. Get your thermostat tested regularly to make sure that it’s functioning properly.

Overheating

Most modern gas furnaces feature safety devices for tracking temperature. If this device is damaged or broken, your furnace could overheat and consequently shut off. A damaged heat exchanger likewise discharges heat into areas of your furnace that don’t need it, which causes regular on-off cycles and overheating.

An Inaccurately Sized Furnace

While an oversized gas furnace could heat up your house quickly, it also does so unequally and leads to short cycling. This is because your furnace has to struggle and deliver consistent temperature all throughout your house. In addition, poor insulation could lead to short cycling if you have an oversized gas furnace. You’ll lose most of the heat it produces through cracks, faulty seals, and holes.

Identifying and repairing a short cycling or overactive gas furnace would help keep your energy costs to a minimum and avoid further damage to your HVAC system. It’s vital to identify what’s causing your furnace to short cycle prior to tearing it apart and assuming the worst. When in doubt, consult an HVAC repair technician to help you.