3 Reasons Your Furnace Is Short Cycling (Turning Off & On Too Often)
A furnace will turn off and on periodically throughout the day to keep your home the proper temperature. However, sometimes a furnace will have a problem called short cycling. This is where the furnace keeps turning off and back on during short periods of time. Short cycling may not seem like a big deal, but your furnace turning off and on more often than it should, will cause more wear and tear, along with higher energy bills. If your furnace is short cycling, you need to know all of the reasons that can cause it.
Bigger isn't always better. You might think that getting a large heater will ensure that you whole house heats properly, but it can actually increase your energy bills because of the short cycling. If your house heats too quickly, it will cool too quickly as well. This will cause your heater to turn off and on constantly throughout the day, and it will be in need of repairs much more quickly than if it just heated your home slowly and steadily. You might want to think about selling your large one and downgrading to a smaller size if this is the case.
Clogged Air Filters
Every house has a vent in the wall or ceiling where the air filter goes for your air ducts. This traps all the dust and debris so it doesn't go flying through your home while your heat or air conditioning is running. If your air filter is dirty, the air isn't going to flow through it properly. When the air has nowhere to go, it goes back to the unit and sends a message to your furnace to turn off. This is a very common issue and one that is simple to fix. Look around your home for the large grate (usually square) on your wall or ceiling. Remove the grate cover and you will see a large air filter with numbers on the end indicating the size. All you have to do is buy a replacement from any big box or home improvement store. Pull the new one out and slide the new one in place.
If you have a gas furnace, a bad flame sensor could be the problem. The flame sensor is a safety feature that allows your furnace to shut off if there is an issue. If it is corroded, it needs to be clean or it will keep thinking there is a problem when there isn't and shut off randomly. You shouldn't try to do any maintenance on a gas furnace unless you're licensed to do so because the flammable gas is dangerous.
If you have noticed your heater short cycling, change your air filter and see if it fixes the problem. If not, call a local HVAC professional to check the flame sensor, evaluate the size, or see if it's another issue entirely.