Corroded Flame Sensor The sensor will shut off the gas if it doesn’t sense flames—this prevents a buildup of unburned gas in the combustion chamber. Since the flame sensor is not able to detect fire when it’s covered in dirt or debris, it will continuously close the gas valve and cause the furnace to keep shutting off.

How do you fix a furnace that keeps shutting off?

If your furnace keeps shutting off, check your air vents to see if any of them are closed or blocked in any way. You should keep all your vents open, even in the rooms you don’t use. If your heat exchanger doesn’t get enough air, it can’t transfer enough heat.

Why does my gas furnace keep shutting off?

Your furnace might be shutting off because of a dirty flame sensor. This is common but it is not a DIY fix. Sometimes a furnace keeps shutting off because the flame sensor is corroded or caked in soot. When operating normally, the flame sensor detects flames, and turns off the gas valve when there isn’t any.

Why does my furnace shut off after a few minutes?

A Clogged Or Defective Flame Sensor

If your furnace shuts down after a few minutes, it’s likely due to a faulty or unhygienic flame sensor. This crucial component intends to monitor the gas burner.

Why does my furnace keep shut off before reaching temperature?

A lack of airflow can cause your furnace to stop heating before reaching the set temperature. Ensure there is nothing impeding airflow around your furnace, within your furnace and through your ducts. Check that registers are open, no ducts are damaged or crushed and replace your furnace filter.

Why does my furnace shut off after 15 minutes?

If your air filter is too dirty, it will restrict airflow. Your furnace will then shut off prematurely to avoid overheating. We recommend replacing flat filters once a month, and pleated filters every three months. It’s easy to stay on top of changing your filter by adding a Filter Reminder on your thermostat.

How do I clean my furnace flame sensor?

Quote from the video:
Quote from Youtube video: So if you have a situation like this what you have 90% of the time is just a dirty flame sensor. So we'll go through the steps on how to clean it. So the right side of the furnace.

How do you know a thermostat is bad?

7 Ways to Tell Your Thermostat Is Broken

  1. Thermostat Has No Power. …
  2. AC or Furnace Won’t Turn On. …
  3. Heater or AC Won’t Turn Off. …
  4. Thermostat Doesn’t Match Room Temperature. …
  5. Thermostat Doesn’t Respond. …
  6. Short Cycling. …
  7. Thermostat Forgets Programmed Settings.

Why is my heat not staying on?

Dirty flame sensor – Your flame sensor is an important component of your furnace, as it can detect the pilot light is working properly. If this sensor becomes dirty, the furnace will shut off. This is one of most common problems HVAC technicians see when diagnosing a furnace that has suddenly stopped working.

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.

Can a bad thermostat cause your 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 do I know if my furnace flue is clogged?

How to tell if your exhaust vent is blocked

  1. Furnace doesn’t heat the air. By far, the most common symptom of a blocked exhaust vent is a furnace that doesn’t heat up. …
  2. Furnace heats up for a little while, then shuts off. …
  3. Furnace cover panel gets hot. …
  4. Bad smells when your furnace is heating.

Can a bad flame sensor cause short cycling?

Bad Flame Sensor

When the flame sensor doesn’t sense a flame, it will shut off the natural gas valve to keep it from pumping raw gas into your home, which could lead to deadly gas fires. A bad flame rod shuts off the flame almost immediately after being lit, resulting in a furnace short cycle.

How do I know if my furnace gas valve is bad?

Here are some signs that indicate your furnace has a bad gas valve.

  1. A Gas Leak. This is a major indicator that something could be wrong with the gas valve in your furnace. …
  2. A Total Shutdown of the Furnace. …
  3. A Flooded Furnace. …
  4. Get Expert Services.