Question: I have a Super Quiet 80 Achiever Series by Rudd furnace. It works great when it wants to. Intermittently it will shut down at night and we have to wake up cold in the morning. Troubleshooting reveals the first burner of the 3 always lights like it is supposed to, but the other 2 don’t always follow suit. Sometimes they light off and other times they try twice , fail , and the furnace shuts down till we reset everything and start over. Service tech came out, cleaned the ignitor, checked everything he could think of and it seemed to work well while he was here. He said we could possibly have a low gas pressure problem. I guess I’m looking for some professional input before calling him back and start the high priced guessing game again.
I would really appreciate any input you could give me. Thanks in advance !! Joe
Answer: Hi Joe! Sorry to hear that you are having trouble with the burners not lighting all the way across sometimes. This probably occurs most often when the furnace is cold and trying to light and start. If the service tech did not already do this I would suggest that you turn the furnace and gas off, take the burners out and blow them out with compressed air and use a wire brush to clean them out on the outside. I would unscrew the gas orifices and blow them out with compressed air. I would suggest either cleaning or replacing the flame sensor while you have the burners out. If you need part numbers please send me your furnace’s model number and serial number to our email address: email@example.com and I will give you the part numbers. If you are still having problems with the two burners not lighting properly I would suggest adjusting the gas pressure up on your gas valve. I would suggest turning the adjustment screw counter-clockwise 1/4 a turn and test to see if this helps. Be ready to turn the furnace off with the power switch if the furnace does not light right away because if the gas valve is not adjusted properly it can cause delayed ignition (small explosion) and this is not good. I have seen delayed ignition blow furnace doors off! There is a good Youtube video on how to properly adjust gas pressure on the following page: https://www.youtube.com/watch?v=xvQabz6d_4g Thanks to ACServicetech for making this great video! Your problem sounds like either dirty burners or gas pressure on the gas valve set too low. I hope you can find and fix this problem soon! Steve