guessing its pressure switch stuck open never hear of a gas valve stuck open, that would require power all time. if so replace the board or check the wiring
I have an old Bryant (394had048100). Someone has installed a icm2804 aftermarket control board, some time ago. About a year per owner. It is giving a fault code of "gas valve stuck open"1 led flash.
There is a lot pilot on the gas valve. There is no evidence of main gas leaking. Pressure switch NC to c is closed and NO to common is open. Main limit and a draft sensing limit are closed. Valve will open when 24vac is applied. Inducer motor will run if 120 is applied and pressure switch will switch position. On a call for heat there is an audible click at the board, and about ten sec delay then the code pops up. Also. Tested for continuity on the wires of the molex to their Spade terminals.
My thought is bad ( or improper) board, but it is POE not a definite reason.
I had a replacement gas valve and connected it electrically only, which did not change the fault. I am happy to answer more questions or take readings for you guys.
I know my profile says I am a maintenance manager at a museum. I just haven't updated it in like a decade. I have been working for a small contractor for three years.
guessing its pressure switch stuck open never hear of a gas valve stuck open, that would require power all time. if so replace the board or check the wiring
Camp175 thanks for the guess. It seems to have been the board. Initial call came in at night. Installed an oem board the next afternoon. Fired right up and no issues. For a week.
I don't use those icm boards often, are they crap? Does anyone have a method for directly condemning a board?
I like ICM boards for most applications. They are easily sourced and nice cross reference app. There’s a lot of ways to check boards just like there’s a lot of different board failures. Sometimes a relay, a solder joint, a burnt or failed resistor. I once had a bad internal connection on Common I bypassed it straight to the transformer till I could replace the board for them. I’ve replaced more carrier boards than anything else. Just like I’ve replaced more Trane compressors than any other.
Ran into a stuck open gas valve on a HSI unit once! Imagine one more control on that thing failing the wrong way.
Someone take the aftermarket board and change a jumper to DSI? As long as it sees a pilot flame it will fault if so.
“A dying culture invariably exhibits personal rudeness. Bad manners. Lack of consideration for others in minor matters. A loss of politeness, of gentle manners, is more significant than is a riot.”
― Robert A. Heinlein
Gas valve stuck open means there is flame rectification with no power to gas valve. It assumes gas valve is stuck open
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Bad board, wasn't bringing in the inducer. How scary is that ?