Furnace doesn't kick on

Greg Marshall

My (my mother-in-law's) gas furnace has an electronic igniting pilot light that lights when the thermostat tells the furnace to start. After the pilot light has been on for 30 seconds or so it goes back out without the furnace ever kicking on. The electronic ignitor continues sparking the whole time the pilot light is lit. A few seconds after the pilot light and spark end, something within the furnace makes light "winding down" noise for a couple seconds. That noise seems like it is coming from one of the electronic or other components right inside the cover for the pilot light area. I'm not sure if this noise has anything to do with a bad part that needs to be replaced. My initial thought is to replace the thermocouple and see what happens, but I was just referred to this site, so I thought I would ask for any other recommendations.

Thank you.

ed wallace

no heat

what your mother has is newer furnace with electronic ignition there is no thermocouple or pilot lite the sound of something winding down is the induced draft fan at this point all you can do is fined someone who can repair it you will not be able to fix it yourself

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

Greg Marshall

I can see a spark light a flame at the end of a short section of metal tube, and the flame stays lit for a short period. I am assuming this is the pilot light. Also, there are notes on the furnace that state to not try to light the pilot light because there is an electronic igniting pilot. Thus, I think I have a pilot light.

Mark Hunt

Two things


It may be the sensor or it may be a grounding issue.

The sensor may not be sensing the pilot and therefore it will not tell the main valve to open.

Grounding is EXTREMELY important with electronic ignition systems and this may also be a problem.

In either case, unless you are a heating contractor you will not be able to fix this yourself.

Go to the "Find a contractor" page on this site to find someone close to you.

Mark H

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

Dale

What you have

I think you have a flame sensor which trade people call a liquid pilot, probably made by White - Rogers, my guess is you have an old white rogers valve with a bad pilot gas safety switch built into the valve. You will need to call someone, tell them what you have since the fix may be a resistor added to the valve and that way they can bring the resistor.

Unknown

Give us some numbers and control names

on the components and I will be able to help you.