Have you ever had a short cycling furnace? A furnace that only heats up for a few minutes and then cools down again. Well, this article is for you. Here we will explain the steps involved in fixing your short cycling furnace and advise you on choosing a new one.

Why do you have a short cycling furnace?

If your furnace is cycling on and off, it’s probably because the blower motor isn’t working correctly. In most cases, this can be fixed by replacing the blower motor.

How to diagnose if your furnace is short cycling?

Short cycling is when your furnace turns on and off too frequently. This can cause your home to become too cold, and it can also lead to costly repairs. Here are four ways to diagnose if your furnace is short cycling:

1. Check the thermostat. If the thermostat is set to a specific temperature and the furnace keeps turning on and off, then the furnace may be short cycling.

2. Check the insulation. If a lot of heat is escaping from your home, your furnace may be short cycling.

3. Check for leaks. If you notice water or snow collecting on the outside of your furnace, then it may be short cycling.

4. Check for carbon monoxide gas leaks. If you notice a strong odor in your home or black soot on the walls or ceilings, your furnace may leak carbon monoxide gas and cause short cycling.

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What causes a short cycling furnace?

A blocked heat exchanger causes a short cycling furnace. This can be due to a buildup of pet hair, lint, or dust on the heat exchanger. To fix this issue, you must remove the dust and debris and clean the heat exchanger. If the problem persists, you may need to replace the furnace.

How to fix short cycling versus long cycling furnaces?

Several things can cause short cycling, but usually, it is caused by a blockage in the furnace’s air intake. If the air intake is blocked, the furnace cannot get enough oxygen to burn the fuel properly. This can cause the furnace to short cycle, meaning that it cycles on and off repeatedly. 

There are a few things you can do to fix a short cycling furnace:

1. Gather all of the pieces of evidence that suggest your furnace is short cycling. This includes any logs or records of your furnace going off and on, as well as any photos or videos of the furnace cycling.

2. Clear out any obstructions in the air intake. This might include anything from dust bunnies to large branches blocking the way in.

3. Check the combustion chamber for signs of damage or wear. This includes checking for cracks or splits in the metal and for soot or debris buildup anywhere in the chamber. If there is damage, replacing part of the chamber or entire furnace unit may be necessary.

4. Replace any parts that are damaged or worn out, such as the air filter or heat exchanger


If your short cycling furnace is causing problems in your home, there are a few things you can do to try and fix the issue. First, ensure that all the vents in your furnace are open. Next, check for obstructions or debris blocking the intake or exhaust ports. Finally, clean out any dust and dirt clogging up the system. If you follow these tips, you should be able to get your short cycling furnace working correctly again.