Home Heating System Keeps Cycling On And Off? 2 Potential Problems Causing It & Their Solutions

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If your home heating system seems to have developed a problem, then don't wait until next fall to have it repaired just because the temperatures will likely be rising soon. Finding the cause of it now is important to make sure that your air conditioning system works well this summer. In addition, some small problems just get worse as time passes and eventually become larger ones that merit more extensive repairs. 

A common home heating system problem is a system that suddenly begins cycling on and off frequently, which is called "short cycling." If you just noticed this problem with your heating system, then don't ignore it, and read on to learn what the cause may be and how it can be fixed. 

1. Dirty Furnace Filter

The first question to ask yourself if your furnace is cycling on and off frequently is when you last cleaned its filter (if it is re-usable) or changed it (if the filters are disposable). When your furnace filter is covered with a thick layer of dust, dirt, and pet hair, it can cause many furnace problems, including increased furnace cycling; the "high limit switch" of your furnace causes it to shut off when it gets too hot. A dirty filter can cause your furnace to overheat rapidly when it turns on, and this switch then triggers it to shut off to keep you safe. 

If you can't remember the last time you cleaned your furnace filter or you haven't cleaned it in over a month, then cleaning it may be a simple fix to your problem. You may have to remove the front panel of your furnace to access the filter. Once you locate it, remove it and clean it with simple soapy water. Then, let it air dry before you place it back in your furnace. 

If this doesn't fix your problem, then at least you have a clean furnace filter and can eliminate that as the cause of its frequent cycling. 

2. Thermostat Problems

If your furnace is not turning off due to a dirty air filter causing it to overheat, then another possible cause of your problem is a malfunctioning thermostat. When you set your thermostat at a specific temperature, it sends a signal to your furnace to turn off when it senses that temperature in the room. It may be sensing that the room is warmer than it is or may simply have "gone bad," causing it to act erratically and send false signals to your furnace. 

To help determine if your thermostat is the cause of your furnace's short cycling, first replace the batteries if it is battery powered. Next, turn the power to your heating system off and remove the thermostat cover. Clean any dust from the inside of the thermostat with a soft cloth and check for corrosion and/or shorted wires. If you notice any obvious problems, then you likely need a new thermostat. 

If you don't notice any problems, then adjust the thermostat's heat anticipator to a "longer" setting. This may improve your problem. If it does not, then call a residential heating repair expert to examine your thermostat and the rest of your home heating system to see what the problem is. 

If your heating system is turning on and off much more frequently than it used to, then don't ignore this problem and think it will just "go away" next year. Clean the furnace filter, check to make sure the thermostat hasn't gone bad, and then call a residential heating repair expert if the filter and the thermostat don't seem to be the problem.