Why does my furnace keep turning on and off?


Diagnosing a Furnace that Turns On and Off

There are a couple of different reasons this may be happening and one or more of the reasons may be happening at the same time.

Furnace is Over-Sized for Your Home

First, it is possible that you have a furnace that is over sized for your home. An over-sized furnace will short cycle or turn off and on frequently. This happens because too much heat is put into the house too quickly. The heat satisfies the thermostat as it is supposed to, but when a house is heated up quickly cold pockets of air are likely to be left because the fan of the furnace did not operate long enough to evenly distribute the warm air throughout all parts of the home. Because those cold pockets are left in the home the warm air is quickly mixed with those cold pockets and drops the temperature in the home which forces the thermostat to call for heat. This cycle repeats causing the “on and off” cycling of your furnace.

Poor Home Insulation

A second reason that is likely in older homes is the overall insulation factor of the home. If a house has poor insulation in the walls/attic space and low quality/leaky windows allowing the heat to escape the “heated envelope” too quickly it will cause significant temperature swings. The furnace and thermostat will react to those temperature swings and once again you will notice the continuous “on and off” cycle.

Furnace Needs Repair

A third reason could be a mechanical failure, or furnace repair is needed. We depend on our furnace on a daily basis just like we depend on our vehicle for transportation. But we are more likely to get routine maintenance done on our vehicle because if we don’t our motor vehicle we leave us on the side of the road walking. Our furnace will do the same thing without routine furnace maintenance; it will act erratic and turn on and off, or just fail all together and leave us stranded with a cold house. If you have not had your furnace serviced this season, and it is cycling “on and off” quickly or appearing to “short cycle” you should call today 505-761-9644 and we can get one of our qualified technicians to perform a furnace inspection.

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furnace-buying-guide-small-thumbnailThis guide was designed to provide you with valuable information when replacing your furnace. If you are considering replacing your furnace get all the information you need to make an informed decision.

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