How should a furnace flame look?
The burner flames from your natural gas furnace should look blue or almost completely blue. A healthy natural gas furnace flame is characterized by a roaring blue flame with a light blue triangle in its center. There may be a tiny tip of yellow.
Why does the fan turn on when the furnace is on?
This will cause the fan to automatically turn on when the furnace is heating and shut off once the call for heat stops. If your fan limit switch was already set to AUTO (not pressed in), then you most likely either have a problem with your thermostat wiring or the fan limit switch is bad.
Why does my furnace make so much noise?
If you hear your furnace making noise it could be a problem with the fan that cools down the furnace. This is caused by the fan bearings being worn out. So to be fixed the bearings will need to be replaced.
What should I do if my Furnace Fan is still running?
If your furnace fan is set to AUTO and is still running, then move on to the next section. Second, troubleshoot for fan limit switch problems. Your fan limit switch is located directly under your furnace hood and controls when your furnace blower turns on and off.
Why does my furnace light go out quickly?
Symptom – Burner lights off, but goes out quickly. What is it? – This symptom is often caused by a dirty flame sensor that can be easily cleaned. Not all furnaces have a flame sensor, but if your furnace has one, it will be mounted close to the burner with the metal rod positioned in the flame.
This will cause the fan to automatically turn on when the furnace is heating and shut off once the call for heat stops. If your fan limit switch was already set to AUTO (not pressed in), then you most likely either have a problem with your thermostat wiring or the fan limit switch is bad.
When does the furnace blower turn on and off?
In normal operation, your furnace blower fan should come on 1.5 to 3 minutes after your thermostat calls for heat and should turn off several minutes after the heating cycle ends. Your blower should run constantly until the heating cycle ends.
Why does my furnace make a loud noise when I Turn on the heat?
This is caused by the fan bearings being worn out. So to be fixed the bearings will need to be replaced. If the loud noise happens only when the furnace starts to turn on then this problem is called “delayed ignition.” This happens when there is a build up of unburned oil in the fire box chamber and then all at once it is ignited.
If your furnace fan is set to AUTO and is still running, then move on to the next section. Second, troubleshoot for fan limit switch problems. Your fan limit switch is located directly under your furnace hood and controls when your furnace blower turns on and off.
