I have been working on our coach with a vengeance there are many things wrong with it but we had 27 degrees last night and my heat pumps will not kick on which is on the list of repairs, so I turned on the aquahot which got hot and turned on the thermostats and all the fans came on but only heat in the galley register and my water tank is warm, the bathroom bedroom and closet has no heat. I unplugged all three relays and installed one relay at a time and all three pumps come on, I banged on the check valves as I've read and then took this thermo image of the pumps in operation, shows hot water is past the check valve but not returning on 2 pumps. Could there be an air lock?
Jack, the next try is to remove the radiator cap on top of the heater, fill the coolant tank with distilled water to completely full. Attach a radiator pressure tester and pump up to 15 psi and turn on the pumps. That will prime the pumps.
If pumps are running and fans blowing cool air then priming followed by another rap on the check valve will get you going. Only rap the valve with pump running.
Rudy Legett
2003 Foretravel U320 4010
ISM11 450 hp Allison 4000R
Factory Authorized Aqua Hot Repair Center
Southeast Texas Area
