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View Full Version : Induced draft furnace won't light


paulson
Oct 24, 2010, 07:02 AM
I have a Tempstar induced draft furnace. I woke up this am to a cold house and the induced draft motor running non-stop. I have recycled the circuit breaker. When I turn it on, there is an initial click (after 5 seconds or so) and a light on what looks like a control module goes from amber to green. Then after 40-45 seconds there is a distinct click, and a few seconds later a quieter click. It's like it tries to light and then discovers something wrong and gives up during the process. I am a DIY-er in most areas, but have little HVAC experience.

Joshdta
Oct 24, 2010, 02:52 PM
Are you seeing the ignitor glow? If not most likely bad ignitor

paulson
Oct 24, 2010, 03:40 PM
You are correct, it was the ignitor. A friend had one for his old furnace that he gave me. Unfortunately, when taking off the shield to get to the ignitor, I broke something else. There are two wires leading to a small, cylindrical black plastic piece that is attached to the shield, with a metal base. I assume it is a temp indicator/protector of some type? While trying to pull off the leads, the plastic piece broke out of the metal base. In order to test the new ignitor, I put a jumper wire between the two leads. What is that piece, and would it be safe to leave it jumped overnight so we have heat? I'll get a new one tomorrow.

Thanks!

Joshdta
Oct 24, 2010, 03:59 PM
Post a pic of the piece, most likely it is a limit of some sort or a role out switch. Most units have more then 1 limit so it should be OK to leave it jumped for the night. But still needs replace.

paulson
Oct 24, 2010, 04:42 PM
Is it a bad idea to jumper the heat limit switch overnight?