Or did you remove the existing wires from the GV? If so, how was the circuit completed?
Removed existing wires from gas valve. Used jumper from r and jumper from common. Once board gave call for gv, manually gave gv 24v from terminal block on board.
Not sure if this is a good thing or a bad thing, but it worked. Allowed us to rule out gv and find the real problem. Also able to determine gas pressure.
True, on this particular Trane, the board controlled gas valve on its own mini circuit, per the 12 pin plug.
Great idea, disconnecting existing wiring on the valve and running a 24 and common off the low voltage coming in, basically bypassing the board control, then testing the opening of the valve by the outgoing pressure..Thanks!
encountered a similar problem (on an l.p. gas system) and found it to be the second stage regulator locking up as soon as there was a slight drop in pressure,
could be bad solenoid coil in valve, weak transformer, voltage drop across pressure switch (check w/ volts not continuity), overloaded transformer (disconnect all peripherals and jump unit out at IFC)
If the PS is in series to the gas valve, then my money would be on a volt or 2 drop across that switch
Check if it properly grounded,than check gv valve.
If if you or anyone else has 10 volts between the neutral and the equipment grounding conductor, you've got some work to do there my friend.