How to service unit heater "ADP"

[@alexl5656]

I’m trying to troubleshoot my dads adp heater from a far. He’s in Montana and I’m in Wa. His heater runs for about 1-1/2 mins then flame shuts off. I sent him a new flame sensor and still does same thing. He’s not getting any codes when burner shuts off. So it comes on runs 90 secs and burner shuts off for about 30-40 secs then ignites flame again and repeats same cycle. For some reason flame keeps going out. It is not hi limit switch and I don’t believe it’s diaphragm switch either.

[@Calgarysheatpumpguy]

would you happen to know age of the unit or model/serial number? this will make is easier to help i do have a few question - does the blower motor run at all during this 90 sec cycle? - is the gas valve warm to the touch after running?

[@bradz1321]

Mine is clicking and the blower motor won’t run