Raypak 406a hi limit 1

[gatorson]

Hi,

I'm receiving a hi limit 1 error after the water temperature hits about 95 degrees F. The unit door gets pretty warm to the touch. I recently replaced the unitherm governer but not the bypass. I believe the hi limit is working properly considering the unit itself is becoming warm (greater than 135 degrees F). The water flow is strong and I do not hear any rattling. Is the next culprit most likely the bypass spring? The unit will also properly refire once it has cooled down enough.

Thoughts?

 

[ajw22]

@Pool_Medic @swamprat69 @kadavis thoughts?

 

[swamprat69]

Some things that could cause overheating are low water flow, overfiring (not normal for gas valve to go out of pressure adjustment), slow movement of combustion products through the heater i.e. blocked or partially blocked heat exchanger. From the manual that I looked up it does not appear that you have an induced draft blower, but only natural convection through the heat exchanger. I would check the heat exchanger for dirt/blockages. That may explain why the door gets pretty warm as the flue gas can't follow its normal path through the heater. I haven't physically seen this heater, so I would also check for any blockages after the heater exchanger through the vent termination.+