Gas furnace wont stay lite

Dec 23, 2007

- Thanks for the clarification, First we ned to start eliminating the culprits. As this is an intermittent problem, meaning it works and sometimes it dont work. So lets start with the thermostat. remove the cover to expose the wiring. You should see red=power, white=heat, green=fan and yellow or blue=cool. make a jumper wire or remove one of the wires whichever is easiest, and connect the red to the white. Dont be afraid of being shocked you probably will not feel anything, just be careful not to touch anything else with the wires, because it may short out the transformer. If you will be more comfortable cut the power. Anyway this will by-pass the thermostat and the furnace will run continuously. If the heat doesn't cut out, that's it, replace 't'stat. If you have the problem still then, we need to look at the limit control or thermal disc if you have one. Lets try this first and let me know.