Solved this one myself but figure I'd post here in case anyone else has a similar problem. If your Suburban water heater will light, stay fired, but won't get the water hot it's the thermostat. If running on propane check for +12-14V on the input of both the thermostat and the over temp relief switch, if they're both present but there's no voltage on the output side of the thermostat then it's dead. The thermostat is behind the reset panel and looks like this:
Check for voltage on the side with the spade connectors referenced to the case and then opposite that on connectors connected to the commoning rod. Btw there's a part of the startup sequence where there's no voltage on the input side so if you don't get a reading wait 15-30 seconds and try again.
Check for voltage on the side with the spade connectors referenced to the case and then opposite that on connectors connected to the commoning rod. Btw there's a part of the startup sequence where there's no voltage on the input side so if you don't get a reading wait 15-30 seconds and try again.
Not exactly......
You see if no DC voltage thru the set of t-stats...no DC to circuit board
No DC to circuit board....No DC to gas valve/spark electrode...no lighting of flame/no heating of water
With switch ON.DC goes from switch to High temp t-stat then thru connecting wire to normal temp t-stat.
If Normal temp t-stat opens (130*F) then DC will not go to circuit board and heating cycle shuts down...but you will still have DC up to normal temp t-stat (constant)
If normal temp t-stat FAILS...then water overheats and High temp t-stat opens (170*F) shutting down DC to normal t-stat/circuit board.
High temp t-stat has to be manually reset....but you will still have DC to High temp t-stat (constant)
Flame ON..water not hot??
Either water heater is bypassed or empty
You see if no DC voltage thru the set of t-stats...no DC to circuit board
No DC to circuit board....No DC to gas valve/spark electrode...no lighting of flame/no heating of water
With switch ON.DC goes from switch to High temp t-stat then thru connecting wire to normal temp t-stat.
If Normal temp t-stat opens (130*F) then DC will not go to circuit board and heating cycle shuts down...but you will still have DC up to normal temp t-stat (constant)
If normal temp t-stat FAILS...then water overheats and High temp t-stat opens (170*F) shutting down DC to normal t-stat/circuit board.
High temp t-stat has to be manually reset....but you will still have DC to High temp t-stat (constant)
Flame ON..water not hot??
Either water heater is bypassed or empty
