this furnace has been the most reliable in our fleet. nothing but change the filters for 5 years. but the gas valve just started dropping out if you touch or even brush the harness. seem to have narrowed it down to the long 5 pin (4 used) connector that is part of the circuit board and effectively mounts this board to the pair of main solenoids (there is a third solenoid with a two wire plug that engages for 25% boost to highest btu operation. this is unaffected but doesn't help because the main solenoid is the gas shut off.
The main solenoids have 4 2" long flat prongs about 3/16" wide , 2 for each solenoid , to carry the 24V to each head. the center prong on this 5 pin setup is not used on this valve. both the prongs which are exposed once the circuit board is removed and the slightly sprung contacts in the plastic covered connector integral to the circuit board have slight darkening where they have been making contact. not black carbon but it appears to be just enough of a surface oxidation of some sort that any shaking whatsoever causes the conduction to collapse and the valve closes. sometimes the furnace will recycle but sometimes it won't light unless i apply pressure to the connector. then everything is fine for a few cycles and then the nightmare starts again.
i can't imagine i'm lucky enough to be the only one who has run into this problem. I have another valve on the way but i wonder if the springs in the connectors wear out easily on these and i'm going to run into the same problem on the new valve in a few years. and its frustrating because there isn't anything wrong with the valve itself, i just cannot get these connectors to maintain connection. it would be very finicky but i suppose i could solder wires from the solenoid tabs to the circuit board. anyone else dealt with this? all brilliant ideas accepted, along with commiseration.
thanks
The main solenoids have 4 2" long flat prongs about 3/16" wide , 2 for each solenoid , to carry the 24V to each head. the center prong on this 5 pin setup is not used on this valve. both the prongs which are exposed once the circuit board is removed and the slightly sprung contacts in the plastic covered connector integral to the circuit board have slight darkening where they have been making contact. not black carbon but it appears to be just enough of a surface oxidation of some sort that any shaking whatsoever causes the conduction to collapse and the valve closes. sometimes the furnace will recycle but sometimes it won't light unless i apply pressure to the connector. then everything is fine for a few cycles and then the nightmare starts again.
i can't imagine i'm lucky enough to be the only one who has run into this problem. I have another valve on the way but i wonder if the springs in the connectors wear out easily on these and i'm going to run into the same problem on the new valve in a few years. and its frustrating because there isn't anything wrong with the valve itself, i just cannot get these connectors to maintain connection. it would be very finicky but i suppose i could solder wires from the solenoid tabs to the circuit board. anyone else dealt with this? all brilliant ideas accepted, along with commiseration.
thanks