Jandy LT Heater Help

Hello,
Just fired up our heater for the first time in about two months today. Heater ran for a few minutes and then cut off. The service light is flashing and the ES 1 indicator light is flashing. According to the manual this could be caused by one of the following:

1. Flue gas vent switch tripped. (manual reset) Verify proper fan operation. Check for restriction or blockage of flue. Reset switch after problem is
corrected.
2. Vent switch fault. Identify and correct loose connections or replace
switch. Refer to qualified service personnel.
3. Fusible link fault. Check for proper clearances around heater and for
adequate room ventilation if enclosed. Inspect for blockage or restriction at discharge or flue. Refer to qualified service personnel.

The first one indicates to reset the gas vent switch. Anyone know where I can find this reset switch? I checked the flue vent and it appears to be free of debris. Does anyone have any other suggestions as to what could be causing this?

Thanks!

I found an owner's manual on jandy.com that contained a Professional Maintenance and Service section for my heater model. (It's actually the same manual, but contains one additional section for Professional's) After removing the top of the heater as the manual instructed, I located the Exhaust Temperature Limit Switch. The switch has a very small red button in the center. All that was required was to push the red button on the switch to reset the circuit. Everything is as good as new. There must have been some debris in the exhaust vent which caused the circuit to trip. Manual states that the switch trips at 305 degrees.

Hope this helps if anyone else has the same problem.