Two Stage Gas Valve Problem

[rosebud]

The two stage gas valve (White Rodgers 36E54-201) in a Trane XV90 LP gas furnace is giving me fits. The first stage LP gas pressure is supposed to be adjusted to between 4.0 and 4.5 inches of W.C. The problem is that the gas valve doesn't maintain this setting but drops lower and so sometime during the night, the furnace won't stay lit due to the low gas pressure. The inlet LP gas pressure is 12 inches of W.C. I suspect there is a mechanical problem with the first stage adjustment mechanism because the adjustment is made with a hex key wrench and as I am pulling the hex key out of the adjustment screw, the manometer reading changes and I have to try to adjust again. It's like the adjustment screw is stripped out of its mechanism in the valve. Has anyone seen this before? Is there a way to fix it or does the valve have to be replaced? Thanks.

[41gasman]

Not specific to your gas valve but I
have had the little"screw" fall through
the threads trying to get pressure up.
Also did you set the high fire first?
One of the two stage furnaces I installed
sometime ago you had to set high fire first.
Low fire pressure was relevant to high fire
evidently.
Hope this helps.

[rosebud]

41gasman,
Thanks for the reply. I checked the 2nd stage pressure and it is set properly at 11 inches of W.C. You said that you have had the screw come out of the threads, were you able to get the screw back in the threads or did you have to replace the valve? Thanks.

[always learnin]

Rosebud:I had a furnace a couple of years do the same exact thing as yours on a relativly new install. Trane had a service bulletin on thise. It was a fix-on-fail only(I think).You need to call your trane dealer to see if it is still covered under warrenty(may not be any longer.)The fix is to change the valve.Hope this helps.

[41gasman]

No I did not have to replace the valve.
I was able to get the allen head back in
the screw. Shear blind luck(I mean skill lol
Was scored sh*tless of piercing the little
diapham at the bottom though. Had the HO
in my ear in crawl no less.
GOod luck,And may the gas gods be with you!

[41gasman]

Rosebud, Should of said scared sh*tless!
Sorry for the typo.

[airconman]

there was a problem with the gas valve on propane the low side backing out. It has been fixed ... this was two years ago... if they worked they were not changed. Trane should supply a new gas valve to take care of this. However if on natural gas it was not a problem.

[rosebud]

Thank you all for your assistance. I have been trying to get a copy of the service bulletin and find out if Trane will give me a new gas valve. Called a local Trane dealer and he claimed he didn't know anything about service bulletins and I should call Trane Corporate. He gave me a phone number for Trane and it was disconnected! A commercial Trane office here in town gave me the number for the Trane "Dealer Service Center" ???. I called them and had to leave a message. Was told they would get back to me within 48 hours. I'm still waiting. I sent an e-mail about 4 days ago to Trane Corporate through their Web site. They sent me a note back asking for model numbers, serial numbers, installer name, service/repair history, etc. etc. I got them the info they wanted and am still waiting for a reply. How hard can it be for Trane Corporate to cough up a service bulletin???? I am sure there is some kind of number associated with this bulletin. Do any of you know what that might be? I assumed that the local Trane dealer would have all the service bulletins but I'm not getting any cooperation.

[airconman]

call this number 800 800 7580 don't tell him where ya got his number talk to BIG JOHN only.... he is one smart guy he'll remember

[amanacalgary]

That particular gas valve is capable of adjusting both the low and high pressure settings for either nat. gas or propane. If pressure won't hold, there must be an internal problem with it. DON'T MESS WITH IT.....Have it replaced by a certified technition.

[blueconnect]

Did anyone find a Trane or maybe WR Service Bulletin associated with this issue. If you did please post the bulletin number.