Furnace Repair Vaughan

technician repairing short cycling furnace

Why Does My Furnace Keep Shutting Off?

Sometimes your furnace leaves you feeling cold again almost immediately after you turn it on. It is quite a significant annoying and devastating problem, especially when the furnace is desperately needed. Why does my furnace keep shutting off? This post provides all your answers.

When a furnace turns on and off, we refer to it as short cycling. Apart from just being annoying, this can also escalate your bills to very high levels, and it might end up being so expensive. So, why does my furnace keep shutting off? And how do we resolve short cycling? Let’s find out.

Common Issues That Cause the Furnace to Keep Shutting Off?

A faulty thermostat

When your furnace shuts on and off, check the thermostat settings first. Ensure that the temperature settings are correct and set to “Heat.” If the problem persists, your thermostat may be faulty. Contact an HVAC professional for advice.

Dirty air filters

The air filters are what make sure we have clean air in the house. Now in the process, the air filters may be full of dust particles and other debris. 

A dirty filter obstructs the airflow, making it very difficult for the furnace to perform well. When there is an excessive build-up of hot air around the furnace, the system automatically shuts off for safety purposes to avoid blowing up.

A corroded flame sensor

The flame sensor sits in front of the pilot flame. Its role is to confirm that there’s a fire present when the gas is open. Thus the flame sensor is a safety element to inform homeowners that the flame is out.

Corroded flame sensors cannot sense if the flame is going or not. Thus, the flame could extinguish while the gas remains open. This deadly situation would pump poisonous gases into your home or cause an explosion.

Faulty igniters

Ignitors light the pilot light. When they’re not working, however, they cannot ignite the pilot light. Thus, the furnace stops working.

Non-working controls

Some controls on the furnace are automated, while others are manual. If the computerized controls malfunction, they may detect the wrong temperature or react wrongly to it. 

The furnace is too large for the home

When the furnace is too large for the home, it heats the house very fast. When the room reaches the desired temperature, the thermostat signals the furnace to shut off. The rapid heating process could cause the furnace to turn on and off repeatedly during the day.  

A clogged vent

The vent is the main exhaust channel. It cleans the air within the furnace. When it is clogged, the furnace overheats, which will prompt the system to shut down. The vent should be clean at all times to make sure there is sufficient airflow.

What to Do When Your Furnace Keeps Shutting Off

The furnace is the most helpful device in the heating process. It should be working at all times, and it should always be clean. Sometimes you may notice that it is stopping and going repeatedly.

Many factors could be causing short cycling. If the troubleshooting methods above don’t resolve the issue, call a professional to assess your heating system, determine the problem and fix it. 

During regular cleaning and furnace tune-ups, you may be able to locate issues before your furnace shuts down. 

Why Does My Furnace Keep Shutting Off – Conclusion

It is common to hear someone ask, “Why does my furnace keep shutting off? “Because the furnaces get down sometimes or sometimes we buy too big furnaces. All those problems we have highlighted above can substantially change the normal functioning of the whole system. That is why we need to make sure that the entire system is sufficiently functioning. 

However, many of the system problems can be regular servicing in terms of cleaning and furnace tune-up. Those would keep the system up and running. The main reason your furnace would keep shutting down is that some parts are malfunctioning or there is a small space to heat, which makes the work a small one. 

So they would heat it quickly and get off until there is a need to start again. Always make sure you go for the right furnace size and maintain it regularly to keep it working.