I have a York forced air gas fired heating system with I guess a direct ignition instead of a standing pilot light. When the system comes on, the blower comes on and then a couple of seconds later the gas valve clicks and some gas goes through but no ignition. Then the gas valve clicks again but still no ignition and the blower continues to run blowing cold air. I checked all electrical connections and everything is tight . I don't see anything trying to ignite. The gas line goes through the gas valve then through 4 tubes with a thermocouple maybe on the left side and I guess a hot service ignitor on the right side. Can anybody help me with this? Thanks Mark

Exact model number?

I have the same issue, my York "TG8S100C20MP11" furnace does three attemps to turn the heater on, but it fails. After the third attempt it just starts and blows cold air.

Unfortunately 2 different techs haven't been able to determine what the issue is since it happens randomly, and the times they come here to check it, it never does it, one of them keeps saying that my air return duct is incorrectly designed and the heat is acumulating and that's what makes the limit switch turn the heat off.

I dismissed this theory since some times the furnace will not work even if it had a whole day off, so no way that there is heat acumulated.

The other tech states it could be a sensor that assures that the four gas pipes are conducting the gas.

any how I still have th same issue, any help would be appreciated.

Thanks

The other

Has the flame sensor been cleaned yet and was it cleaned well?

Thanks for the quick response.

The flame sensor has not been cleaned, my heater is just one month old, and it has done this since they installed it. Is there still a need to clean it?

How can I clean it myself? (I know which sensor it is)

Usually on calls like this it is the flam sensor problem. You can clean it yourself but be careful of the ignitor if attached. Use fine sand paper or steel wool. Since I do not know exactly what yours looks like I will post a few pics.