No second stage on AS AUXI00R, Need Help

[bobby1]

I can't get the second stage to fire on an American Standard AUX100R948W converted to LP. It has a new Vision Pro 8000 Tstat that's programmed for 2 stages. We checked the wireing and gas pressure and found the static to be around 12" that drops to 10" when the low fire is running along with all other gas appliances in the house. You can't get the high adjusted high enough to reach the 10.5-11" that they call for. Both adjs screws are bottomed out in the valve The 2nd stage is supposed to start 10 mins after the first. I also tried to jump the R, W1 & W2 with no results. Could the low gas pressure be the problem?? Should'nt I still be able to get the 2nd stage to fire. Is there a way to test the board with a VOM ?

[docholiday]

Static gas pressure means..... well, Nothing. Inlet gas pressures are for when the unit (and other appliances) are running. This has to be adjusted by someone qulified. Also the piping may be simply too small.

There are a number of reasons why it will not go into high fire, and yes a meter may be required.

[trane]

Bobby, I would like to help and tell you just what to do but you really need to get someone involved that has worked with LP gas more and the two stage furnace. There are several things in your post that tells me your not sure of what your doing and this is not something to guess at.

[mark beiser]

No way to tell from here what may cause it to not go into high fire.

As for the gas pressure problems, did you install the regulator spring that came in the LP conversion kit? It is a really fine spring and easy to miss/drop (This from first hand experience of someone who had to carefully sweep a wood floor then go over the dust pile with a magnet!). Without it, you will never get the pressure high enough.
If you didn't already know, you have to adjust the gas pressure for high fire before you adjust low fire when you convert to LP.

[heatmon]

I'm going with what trane said- get someone with experience with a natural gas to lp gas conversions involved, especially someone with two stage burner experience. Natural gas is very low pressure (larger orifice sizing compared to lp), lp is higher pressure (with smaller orifice sizing, also more btu's per cu. ft, as compared to natural gas). I can't read your post and place my post at the same time, did the conversion kit come with new high & low fire pressure switches or just new burner orifices and a main gas supply pressure regulator?

[beenthere]

Have a more experienced tech come with and help you.

[bobby1]

The spring is installed properly, I am certified, and I have some experience in the HVAC field but this unit is a little over my head. I did get a more experienced tech involved and we still can't solve the problem. Mabye it is just the line pressure and/or pipe size. The lack of tech info,a very limited troubleshooting section in the installers guide and poor accessability to a factory tech line makes matters worse. There are much lesser products and appliances that give you a tech # or try to direct you in the right direction. There needs to be step by step instructions for the installer to troubleshoot/test the unit and rule out causes to pinpoint the problem. Even the complicated flashing indicator lite trouble code chart is minimal and does not include the flash sequence that we're getting (the 42nd flash is red).If it's supposed to be self diagnosing then why dosen't it flash a code for the 2nd stage not firing (even when jumped). No switches were in the kit, just orifices, spring and a barbed fitting and hose to tap into the Gemini valve. Thanks

[beenthere]

Can you hear the inducer speed up.

You should put a monometer on the inducer to see if its speeding up.

Did you check for voltage at the valve.

[1972torino]

QUOTE:bobby1
The lack of tech info,a very limited troubleshooting section in the installers guide and poor accessability to a factory tech line makes matters worse. There are much lesser products and appliances that give you a tech # or try to direct you in the right direction. There needs to be step by step instructions for the installer to troubleshoot/test the unit and rule out causes to pinpoint the problem. Even the complicated flashing indicator lite trouble code chart is minimal and does not include the flash sequence that we're getting (the 42nd flash is red).If it's supposed to be self diagnosing then why dosen't it flash a code for the 2nd stage not firing (even when jumped).
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i dont want to sound rude but you and the other tech. really need to get someone with more experience to help, pissing around with nat.gas\lpg and oil without the proper know-how is dangerous to yourself and your customers! as for tech. support Trane & American Standard have exellent FSRs

[heatmon]

bobby1,

To get the paperwork, any tech documentation for Am Std- Trane, you need to go to your distributor and give them the model & serial & tell them what kind of documentation you need.