I have a Trane XE80 that I'm trying to fix. LED on the control board flashes 4 times indicating a Hi Limit switch open. Where is the hi limit switch? I've metered all of the sensors that I could find and nothing shows open. Does anyone have a part number for the switch? Blower comes on but I don't see any ignighter glow.
theres usually a couple of limits if its an upflow theres one on the bulkhead wall looks like a flat piece of fiberglass with 2 wires on spadeclips coming out of it might also be one in the blower compartment and possibly one on each side of the burners these are more like a silver discagain with the 2 wires. look on the wireing diagram there usually all wired in series so you can read them all out at once once you figure out where they are and what color wires there using