Trane heating system shuts down after 10 minutes of run time

[FordMan59]

Sorry, I can't give system model number, but the unit is at the church I attend. This is a Trane propane gas unit. This morning the thermostat would call for heat, the unit would start heating, run for about 10 minutes then shut down and not restart, but we could turn the breaker off then back on and the system would immediately restart, run another 10 minutes and go through the same failure. During the 10 minutes of run time if you were outside beside the unit you could hear the unit kick in and out several times before it would finally completely shut down. The indoor temperature never would hit the thermostat target temperature. Anyone have any ideas? I'm thinking about going back to the church tomorrow to see what it will do and see if I can find the problem. I don't know or claim to know anything about such a system so any suggestions are appreciated. Unless it's something obvious, we'll probably end up getting a HVAC technician to look at it before next Sunday.

[HayZee518]

It seems you are experiencing a high temp cutout and lockout as you need to shut off control power, then restore it to run. Is this hot air or a hydrionic heat?

[FordMan59]

It seems you are experiencing a high temp cutout and lockout as you need to shut off control power, then restore it to run. Is this hot air or a hydrionic heat?

Hot air. Any suggestions what to look for that may cause a high temperature cutout/lockout?

[HayZee518]

look to the combination fan start relay somewhere on the plenum ductwork. it would be a box approx 2 1/2 inches X 4 inches with a removable cover. There may be a white knob sticking out from it. inside is a helix coil that turns when its heated and operates a set or two sets of contacts, one of which is the high temp cutout.

[KDGrayson]

Check for the flash code, if a limit was tripped that can do it, reduced air flow is why usually unless the limit is bad, I suspect the induced draft proving switch is not getting the air from the induced draft assembly to "prove " the inducer motor is running, there is a barbed port that the rubber hose attaches to on the induced drat assembly, ream it out with a drill bit or paper clip.