Short Cycling Gas Furnace

Short cycling is a malfunction that causes your furnace to turn on for short periods of time normally between four and seven seconds.

Short cycling gas furnace. That can cause the furnace to overheat and forces the high limit switch to ride to the rescue by shutting the furnace off. Boiler short cycling occurs when a boiler subject to its own internal thermostat fires up starts operating when the thermostat detects that the water in the boiler has cooled down. A term you probably haven t heard until it. The causes of short cycling vary from minor malfunctions to unit replacing problems.

In other words turning on and off frequently is just a symptom of short cycling. If you notice constant short bursts of activity you re likely experiencing short cycling. When your heating system does not require the boiler to fire the heated water in the boiler s heat exchanger will begin to loose heat to the air around the. The most likely cause of short cycling is the fan limiter which prevents fires and furnace damage by shutting the system down if the heat exchanger becomes too hot.

If the furnace is short cycling between 2 to 5 minutes this could be your problem. This video is part. Boiler short cycling short cycling. If the burner starts and runs for 4 to 7 seconds and it was made in the last 25 years there is probably a flame proving problem.

This issue can be dangerous too since deadly carbon monoxide is dispersed through the vent. Whereas a properly functioning furnace will run for several minutes per cycle. This is another cause of a furnace overheating and short cycling. What causes short cycling.

A short cycling furnace when your furnace keeps turning off and on will typically only run for a minute or two or less before shutting off. Short cycling means the furnace starts but will not stay on long enough to bring the structure up to the set point temperature. What is happening here is the gas is supplied to the burners and the burners light. Furnaces have built in safety systems that prevent dangerous situations like fires carbon monoxide leaks or gas leaks.

If it is blocked the gas won t escape and it can leak out of the furnace and into your home. If your air filter is clogged with dirt it won t allow proper air flow to the heat exchanger. The most common causes of a blocked vent are bird or animal nests. The most common of these is the flame rod failing to sense the flame.

When the gas furnace short cycles and it does not bring the structure up to temperature i give several reasons why and how to fix them.