Hey all, just wanted to pick your brains a little.
Had a call on a 12 year old variable speed Carrier Infinity m# 58VUA060GG. Initially had a fault code 42(inducer RPM out of range). Checked out fault code history and found 31, 32, 42 and 43. Checked all obvious ie. blocked exhaust/intake venting, ventor induction pressure, gas pressure, stat closure, condensate drains, pressure switches and associated tubing.
Now, it's hard for me to know where to even start explaining what it is that I saw. The faults I found were extremely erratic leading me to automatically think BOARD? Code 42 would appear after power cycling without the ventor even starting or only breifly starting. Gas valve would drop out and fault 31, 32 with no actal pressure switch opening. Separated venting and still no change. Tried altering DIP switches one at a time on control board to isolate LO fire/HI fire from emergeny heat switch setting hoping to determine if the microprocessor for variable operation was the culprit. No definate conclusion reached.
I could probably go on and on, but, was just hoping that someone else had experienced something like this with this same model furnace. If anyone has other tech specs, it would be much appreciated. Thanks in advance.