Why does my furnace start then stop?

A furnace that starts then stops is a common issue also known as short cycling. When the furnace cycles more often than this, short cycling is possible – it may also be possible that extreme temperatures are causing the need for more frequent cycles, or your furnace is undersized or requires additional insulation.

What does it mean when your furnace won’t stay lit?

Probably the most common issue when dealing with a furnace that will not stay lit or ignite consistently is a dirty flame sensor. The flame sensor acts as a communication vehicle with the circuit board and tells it when a flame is lit inside the furnace.

What should I do if my furnace won’t ignite?

If your problem is not with your gas line, see if your pilot light is lit, since your pilot light or ignition sensor is the most common culprit behind a furnace that won’t ignite. If this is your first time turning on your furnace this season, keep in mind that it may take a little extra time for the pilot light to turn on.

Why does the gas furnace keep coming on when the pilot light is out?

The flame sensor tells your furnace that the gas is lit. Without this device, your furnace would simply continue to allow gas to flow into your home, even when the pilot light was out. Flame sensors can go bad and occasionally need to be replaced. Poor flame sensor positioning.

What happens when you turn on a gas furnace?

Situation: You turn the thermostat up, the furnace ignites and the burner comes on. The furnace stays on for awhile (maybe 1 minute, maybe 10 minutes) and then goes out. The fan continues to run even though the flames and pilot light go out.

Why is my furnace not staying lit?

When the pilot on your wall furnace does not stay lit, your furnace won’t heat. A number of reasons can cause the wall furnace to not light, including a damaged thermocouple, a clogged pilot orifice and a disconnected gas supply. The pilot has a small opening in its end that can become dirty and clogged with dirt and debris.

Why is the oil furnace not staying lit?

Probably the most common issue when dealing with a furnace that will not stay lit or ignite consistently is a dirty flame sensor . The flame sensor acts as a communication vehicle with the circuit board and tells it when a flame is lit inside the furnace.

Why is my furnace pilot not staying lit?

The most common reason the furnace pilot light won’t stay lit. Bad Thermocouple. A furnace thermocouple is a safety feature that regulates gas flow to your system based on whether the pilot light is on. In simple terms, the thermocouple checks to see if your pilot light flame is lit and turns off the gas flow if it senses that your pilot light is off, so you don’t have gas building up in your home.

Why is my pilot light not staying lit?

The primary reason a pilot light won’t stay lit is simply equipment malfunction. If you’ve checked everything else and the light continually goes out, this is probably the cause. In this case, you may need to replace your pilot light. A pilot light can also keep going out because of a problem with the thermocouple .