You should be able to find a diagnostig cade inside the unit or on the control module itself. If I was to take a guess i would say the unit is over heating and tripping your limit switch. Make sure the filters and coil are clean that switch will open in the low to mid 200's.big waynester said:It will run for about 5 min, then shut off, I get 3 blinks on the status light. I have no book with this unit, so I don't know what this means, but it was installed in late 1999. Is there any thing I can do? I hate to call the guy that installed this.
Check to make sure that the vent for the exhaust is at a downflow angle toward the furnace.if it's sagging water will build upbig waynester said:I think I kind of have it fixed, to much condensation in the vent blower, backed up to the pressure switch hose and got into switch, now I got to figure why this happened