Help With SV9541M SmartValve - http://www.hvacmechanic.com/ Forums
Original message
| WiCkeDuDe
 |  "Help With SV9541M SmartValve"
, posted Tue 7 Oct 17:59:  
Hey guys im looking for some diagnostic aid in getting my Heil furnace going. The furnace is a 9MPD075F12B1 and uses a honeywell SV9541M gas valve. I need help in determining wheather the control board or gas valve is bad.
When calling for heat the furnace does nothing. The gas valve has no "heartbeat", it is a solid green light. The exhaust blower does not kick on. Tracing the blower fan wiring I have 120VAC going into the gas valve but only 1-2 VAC going out to the fan. I jumpered the fan with 110V and it spins up just fine. Testing the ignitor system the thermocouple has 26-27 volts going through both wires. The ignitor element reads 141 VAC. The power to the gas valve is only 18 VAC on I believe the orange wire. Should this not be 24VAC?
Now for the control board, the transformer is feeding out 26 VAC. The board worked fine with the A/C all summer. I have read other forums were the cause was a defective gas valve due to moisture. There is some condensation on the pin connections on the gas valve I can see. Ive also checked my single pressure switch and it is open and closing fine when I sucked on the pressure hose.
Can any one elaborate how I can test for sure weather the control board or gas valve is bad? I am hestiant to buy a new gas valve until I am convinced for sure its bad.
If anyone has any ideas or needs more info please ask. Its getting cold here the last few days :)
[this message was edited by WiCkeDuDe on Tue 7 Oct 18:20] |
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| WiCkeDuDe
| "Re(1):Help With SV9541M SmartValve" , posted Fri 10 Oct 13:12
Isn't 9541 the model of smartvalve? I did try jumping the inducer motor and it worked fine. Again I have 110 volts to the gas valve but it does not pass that to the inducer.
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| jmar
| "Re(1):Help With SV9541M SmartValve" , posted Tue 7 Oct 23:48
smart valve 9500,or 9501 or 9502? Look on valve itself. sv denotes smart valve 95.. denotes series (big help to know) do you have hot surface to pilot ignition or spark to pilot ignition? Im going to assume that you have a sv9501 if so a call for heat generates 90sec trial for ignition. The valve its self controls all operation for ignition, etc, thus the name smart valve. Solid green denotes lockout. Theres a PV connection for pilot valve which opens after ignitor glowes, once pilot flame proven mv main valve opens. Board as far as no heat wont cause the problem with igniton, and burner ligting. But if the inducer is not running there may be an issue on the blowercontrol board with the fan timer relay. Replace your blower control board. Reset power to remove system of lockout and procede from their. Or for testing hot wire the inducer to run and verify system ops from there.
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| | WiCkeDuDe
| "Re(2):Help With SV9541M SmartValve" , posted Sat 18 Oct 12:03
I replaced the gas valve and that solved the problem. I have noticed that the furnace lights up fine but sometimes the main burner will go out and quickly fire back. I hear the gas valve click shut but not the pressure switchs. Could this be a gas pressure problem? The utility put a new gas meter in over the summer now that I think about it.
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| | techshawn
| "Re(3):Help With SV9541M SmartValve" , posted Sat 18 Oct 19:20
measure the voltage over the gas valve when it works strangely. if the reading of voltage is even, the gas valve is at fault.
I like fixing everything.
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