I have an old Airtemp furnace that has a problem. When I turned it on the first time this season the burners would not light. The pilot light ignites and then I hear a click (assume gas valve should open) to supply gas to burners but no joy.:confused: The pilot then goes out for a couple of seconds then it comes back on and it retries again. I'm thinking a thermocouple problem, maybe. This is an Airtemp model 45083F 1421

This is a link to a video of the problem I posted on you tube:

YouTube - Airtemp furnace (http://www.youtube.com/watch?v=euLDpRYn-OI)

Thanks for any help.

maypo52

First take the pilot assembly out and clean the orifice. It has a very small opening which is a numbered drill bit size.Try to not make it much bigger when you clean it out.It looks like this is a white rodgers setup so also make sure the electrode that supplies the spark and sensor combination is cleaned with a fine sand paper or a little steel wool. If you use steel wool make sure any wool left behind is removed from the electrode and insulator because it can cause a grounding situation and not allow the sensor to operate properly.NOTE: you might want to use a little spray lube where the aluminum tube goes into the nut. Sometimes a bit of corossion will develop and cause the tube to twist in the nut when removing. If you can prevent that you will not have to replace the pilot tube.

The pilot flame is coming on but when the main valve kicks on the pilot flame is not strong enough to keep a signal for the safety device. While you are at it I would also remove the burners and clean them out and then vacuume the below burner area. You can also check to be sure the main burner orifices are clear of debris. The main orifices are much larger than the pilot so you can use a small pin to make sure the holes are cleaned out.

Thanks HVAC1000. I will give that a try to see what happens. I'll let you know.

Regards,

maypo52

I took the pilot light section apart and cleaned it up. It was fairly gunked up. I also vacuumed all the junk from the burners and from under the burners. I should have taken a photo to show how much (I don't know what to call it) stuff was laying in and around the burners.

And now I have fire

Thanks for the help HVAC1000

Glad I could help