In the winter, you want to make sure your furnace keeps your home warm and your family comfortable, but homeowners experience short-cycling or overheating complications with their furnaces. With short cycling, the furnace turns on and off frequently. Occasionally it will not make any heat at all before shutting down, and common reasons your gas furnace may be short cycling include overheating, bad flame sensor, dirty gas furnace filter, blocked exhaust vent or heat grates, improper control unit placement, or having a gas furnace that is too big for your home. Your gas furnace may turn off prematurely if it is overheating. Almost immediately after lighting, the gas furnace flame will go out if the flame sensor or flame rod is bad. Your gas furnace can short cycle and overheat if it has a dirty filter. You may notice that your gas furnace shuts off only a few hours before your home is warm. Overheating can also be caused by blocked heat grates, which do not let enough air out. Blocked exhaust vents can also cause overheating and short cycling, but it is a potentially dangerous reason since carbon monoxide can leak through! The location of your control unit matters because if your control unit is getting warmed before the rest of the house, it will cause your gas furnace to turn off prematurely. Most homeowners install the control unit themselves. It's not uncommon for homes to have too important furnaces because the installer thought larger was better. This is not true, and can lead to short cycling of your unit. The best solution, if this is the cause of your gas furnace's short cycling, is to substitute it. Short cycles, temperature swings, and high heating bills may indicate this is the issue.

In the winter, you want to make sure your furnace keeps your home warm and your family comfortable, but homeowners experience short-cycling or overheating complications with their furnaces. With short cycling, the furnace turns on and off frequently. Occasionally it will not make any heat at all before shutting down, and common reasons your gas furnace may be short cycling include overheating, bad flame sensor, dirty gas furnace filter, blocked exhaust vent or heat grates, improper control unit placement, or having a gas furnace that is too big for your home. Your gas furnace may turn off prematurely if it is overheating. Almost immediately after lighting, the gas furnace flame will go out if the flame sensor or flame rod is bad. Your gas furnace can short cycle and overheat if it has a dirty filter. You may notice that your gas furnace shuts off only a few hours before your home is warm. Overheating can also be caused by blocked heat grates, which do not let enough air out. Blocked exhaust vents can also cause overheating and short cycling, but it is a potentially dangerous reason since carbon monoxide can leak through! The location of your control unit matters because if your control unit is getting warmed before the rest of the house, it will cause your gas furnace to turn off prematurely. Most homeowners install the control unit themselves. It's not uncommon for homes to have too important furnaces because the installer thought larger was better. This is not true, and can lead to short cycling of your unit. The best solution, if this is the cause of your gas furnace's short cycling, is to substitute it. Short cycles, temperature swings, and high heating bills may indicate this is the issue.

What happens with short cycling

 

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