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jax 02-02-2007 09:15 AM

Furnace not firing
I have a ten year old Rudd furnace that is not consistantly firing. In December the Inducer Blower died and - thanks to this fourm - I was able to find and new one and have it replaced. After that the furnace worked well for a little over a month when last week it stoped firing. I went to the furnace room to see what was going on when I heard it kick on. It fired for about an hour and cut out again. The inducer is working, and sometimes the furnace fires and other times it does not.

I had someone come out to look at the unit. He cleaned the air intake (said it had gotten some leaves in it) and it fired fine for a day. The next day, the same problem. You hear the inducer start, and sometime the furnace will fire sometime not. Sometimes you will hear it try to start - you'll hear the click that is typical of the furnace starting (I guess the presure switch) and then you'll hear it click off. I had the guy out again and he found a little moisture in one of the lines and tested the presure switch and said everything looked fine. The furnace fired right up...for about an hour. After about another hour it kicked on and worked until this morning.

I'd appreiciate any ideas on what to do next. It's supposed to get cold this weekend.

Thanks in advance,

PATMAN 02-02-2007 10:35 AM

Sounds like you have a dirty flame sensor. this is located in the burner compartment. It may have an orange wire running to it. It's ceramic with a metal rod sticking out of it. It should be on the left side of where the burner flame would hit it when it's running. Try carefully removing it, sanding the metal rod with sand paper and put it back in. Don't crack the ceramic.

jax 02-02-2007 11:34 AM

Furnace not firing
Thanks for your reply. My question is, would the flame sensor explain when when it doesn't fire at all? Equally as often as you hear it click on and then off, it doesn't fire at all. The inducer will start and that's it. Thanks again for your help.

AweMan 02-04-2007 04:01 AM

Furnace won`t fire
Look back through the threads and look for This may help someone with carier ingintion problems { It`s my post } basicaly what it says is to take the gas manifold out and thouroughly clean it. It has a slot on the side that the flames come out of and this slot if dirty { even slightly} will not allow the gas to distribute adequately everytime thereofre causing intermittent ignition. The manifold is the piece between the gas valve pipe orifices and the actual burner, I don`t know your partcular brand furnace but on my carrier you remove the gas valve and unplug the ignitor and flame sensor and the manifiold will slide right out. Be careful of the ignitor it is very fragile and can break easily, you can also have easy access to clean the flame sensor at the same time. Use fine sandpaper to make it bright and shiny.
I hope this helps

astottl 02-22-2009 10:23 AM

testing post:eek:

hvaclover 02-22-2009 12:41 PM

Sand paper:eek:?

Oh each his own.

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