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-   -   American Standard Freedom 90 Furnace not igniting consistently (http://www.diychatroom.com/f17/american-standard-freedom-90-furnace-not-igniting-consistently-164483/)

tjrettig 11-23-2012 08:23 PM

American Standard Freedom 90 Furnace not igniting consistently
 
My American Standard Freedom 90 Furnace only ignites about 50% of the time. It appears that the ignitor turns off a split second before the gas valve is opened. I replaced the ignitor hoping that a new one would get hotter and stay hotter for a split second longer, but it still only works about 50% of the time. I can use a lighter in place of the ignitor and get it to ignite 100% of the time if I do it manually.

Here is video of it failing to ignite:
http://youtu.be/RMZKuhxgXQk

After I took that video, it retried automatically and it ignited like normal. It is really hit or miss. I found two videos of similar furnacing igniting, and it appears that their ignitors stay on longer:

http://www.youtube.com/watch?v=1iOdPVFTwIA
http://www.youtube.com/watch?v=d_ylU...feature=relmfu

The ignitor is part number IGN00054. Is there an ignitor that will stay hot longer, or is there a way to adjust the furnace to leave the ignitor on longer?

Any help would be appreciated. Thanks!

NiNe O 11-23-2012 08:29 PM

check that your outlet gas pressure matches your spec plate for the fuel you're using.

JJboy 11-23-2012 08:38 PM

Also check the igniter resistance....it should be close to 0 ohms.

how 11-23-2012 09:19 PM

That valve should be opening when the igniter is at it's hotest temp.
Board problem or slow gas valve are two other possibilities. If you are getting 24V to the valve a split second after the new igniter is starting to cool off, then you probably have a board issue. If you are getting 24 V to the gas valve when the igniter is hot and the valve is taking 3 seconds or longer to open, then the valve is the issue.( but that's not common)

krez 11-23-2012 10:46 PM

had this same prob with a goodman gmh95, when the ignitor was going out (cooling off) the valve would get the proper voltage, turned out after replacing the valve it still happened, i switched boards, same issue, it turned out to be the small 4 inch wiring harness (comes with valve) that connects the valve to the main board wires, was the issue,, that being said is this a possible solution for you, (wiring to gas valve connections)

beenthere 11-24-2012 07:26 AM

Quote:

Originally Posted by JJboy (Post 1058900)
Also check the igniter resistance....it should be close to 0 ohms.

20 to 100 ohms. Some as high as 140.

hvactech126 11-24-2012 09:01 AM

clean your burners and make sure the manifold orifice for the first burner on the right is clear. While you have them out clean your flame sensor as well (has nothing to do with your current problem, but is good yearly maintenance anyway).

tjrettig 11-25-2012 11:24 AM

Quote:

Originally Posted by how (Post 1058916)
That valve should be opening when the igniter is at it's hotest temp.
Board problem or slow gas valve are two other possibilities. If you are getting 24V to the valve a split second after the new igniter is starting to cool off, then you probably have a board issue. If you are getting 24 V to the gas valve when the igniter is hot and the valve is taking 3 seconds or longer to open, then the valve is the issue.( but that's not common)

Thanks for the suggestion. I checked the voltage, and it looks like the valve is opening right when it receives the voltage, so it doesn't look like a slow valve. It just looks like voltage drops to the ignitor when voltage is sent to the valve - so that really points to a faulty board. I'm either going to replace the board, or wire the ignitor line up to a timed relay that will feed voltage to the ignitor for 30 seconds. My ignitors won't last as long, but I've got some extra ones from troubleshooting this......

tjrettig 11-25-2012 11:26 AM

Quote:

Originally Posted by krez (Post 1058964)
had this same prob with a goodman gmh95, when the ignitor was going out (cooling off) the valve would get the proper voltage, turned out after replacing the valve it still happened, i switched boards, same issue, it turned out to be the small 4 inch wiring harness (comes with valve) that connects the valve to the main board wires, was the issue,, that being said is this a possible solution for you, (wiring to gas valve connections)

Thanks! I will try replacing that wiring too and see what happens.

tjrettig 11-26-2012 06:29 PM

I think it's fixed!
 
I think it's fixed!

While double-checking the wiring and deciding what to do next I noticed that the ignitor had rotated slightly on the screw that secures it in place. Because of that it had come in contact with the metal burner. I loosened the screw and adjusted the wiring to not pull on the ignitor, then tightened it back up and made sure it wasn't anywhere near the burner. That was last night. So far we've gone 24 hours and I haven't noticed any issues. Good timing, too since the last night was one of the coldest so far.

Thanks everyone for the suggestions.

Hopefully someone else will find this post helpfull, too.


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