Why does my furnace start then stop?

This behavior is caused by something cutting short each furnace cycle since your furnace is being forced into a short cycle to keep your home the temperature set on your thermostat. A furnace that is sized properly for your home should start and stop 3-8 times in an hour.

Why does my furnace only runs for a few minutes?





A common reason a furnace short cycles is because the heat exchanger, the part that heats your air, is getting too hot due to a lack of airflow. Once the heat exchanger overheats, it trips the high limit switch, which shuts the furnace down to protect it.

Why does my furnace blower keeps turning on and off?

If your blower is constantly turning on/off when the furnace isn’t heating… …you most likely have a bad fan limit switch. Your furnace fan limit switch is basically a control system that determines when the furnace blower assembly should turn on and off.

How do I know if my furnace is working properly?

Quote from the video:
Quote from Youtube video: Let's check it now let's see if it's working now it's very simple here's what you do go to your thermostat flip with the heat. Turn it up to 90. See if you got heat coming out of the vents. Simple.

Why does my furnace keep shutting off after a few seconds?

So, if your furnace keeps turning off and on too quickly, your thermostat might be malfunctioning or broken. There are several things that could be causing your thermostat to not work properly. The wiring could be old and need replacing, it might need new batteries, or it could be the location of your thermostat.

How do you fix a short cycle on a furnace?





A dirty air filter is the most common cause of short-cycling. If your air filter is clogged with dirt, it won’t allow proper air flow to the heat exchanger. That can cause the furnace to overheat and forces the high limit switch to ride to the rescue by shutting the furnace off.

What might be the problem if the furnace runs but with short cycles?

A short cycling furnace can cause your home heating system to break down prematurely, which can be a big problem during the winter months. If your furnace is short cycling and you can’t seem to get the problem under control, contact the heating contractors at a professional furnace repair service today.

Why won’t my furnace shut off?

On your thermostat, look for the fan settings. There should be two, “ON” and “AUTO.” If it seems like your furnace won’t turn off, the thermostat may be set to “ON” for the blower. Toggle the switch to “AUTO” so your furnace’s blower fan only runs during a heat cycle.

Can a bad thermostat cause a furnace to short cycle?

Thermostat Troubles Can Cause Short Cycling



Your furnace or central air conditioner spends a good amount of energy simply turning on and off, which is why you want yours to run for at least 15 minutes at a time before shutting off.

How many years does a furnace usually last?



15 to 20 years

A well-maintained furnace can last at least 15 to 20 years, but completing annual maintenance and being diligent with repairs can extend its life even longer.

How do I know if my heating element is bad in my furnace?

The easiest way to check this is to turn the heating element on and inspect the temperature of the air coming out of your heating system. If the air is insufficiently heated, very close to, or at room temperature, there is probably something wrong with the heating element.

How do you reset a gas furnace?



Follow these simple steps:

  1. First, turn off the power supply to the furnace by turning off the breaker in the circuit box.
  2. Locate the reset button on the furnace and press it to reset the furnace. …
  3. If the button is popped up, press it down.
  4. Return the cover to the blower compartment and turn the power on.


Does a gas furnace have a reset button?

All furnaces are equipped with a reset button. They are generally red or yellow and are located inside the blower compartment. The reset button is a safety feature that will shut down the furnace when a problem is detected, often a hot or overheating furnace, before it trips the circuit breaker.

Where is the reset button?

Alternatively referred to as the reset switch, the reset button allows devices that utilize it, such as a computer or peripheral to be rebooted. Usually, the button is on the front of the device, next to or near the power button.

How long do you hold reset button on furnace?



Turn the power and main gas supply on the back again. After doing all this, press the reset button, hold for 30 seconds and release it. The furnace will restart, and then you can adjust the thermostat’s setting.

Why do I have to push the reset button on my furnace?

All home furnaces have an easy-to-spot red reset button. This safety feature is designed to trigger automatically, shutting down your furnace when a problem is detected. Sometimes, this will happen by mistake, and getting your system up and running again is as easy as pressing the button.

When should a furnace be reset?

If your furnace doesn’t have any air coming out at all and the pilot light is out, it’s worth it to try resetting the furnace. If this doesn’t work, there may be a problem with the thermostat setting, the power, or the gas line.

How do I get my furnace to kick on?

Thermostat. If your furnace is not kicking on, it can be an issue with the thermostat. You should first make sure that the thermostat is switched to the heating function. Next, make sure that the temperature that you have the thermostat set on is lower than the temperature in the home.