My AquaHot heat exchanger fans in the LR, Bath and BR quit working. I checked all of the AquaHot fuses, OK. I removed and reseated the three relays. When the thermostats are switched on the AquaHot circulation pumps come on but not the blowers. I checked the heat exchanger in the bathroom. With the thermostat on there was 12v to the blower but no blower. Jumping the other wire to a ground point made the blower come on! A ground wire problem? Where are the heat exchanger blowers grounded?
Inside the AquaHot case just to the left of the wire terminal block where the fuses are is a ground stud in the case. There are two smaller wires with ring terminations and two bundles of wires (ground wires) each with ring terminations.
The smaller wires were on the ground terminal stud, a nut was on the stud but loose. The other two larger bundles of wires were not connected to the stud. Maybe a nut came off driving through the I 80 washboard in Omaha. Amazing that everything didn't shake loose. I better go check!
The stud was loose on the case so I tightened up that the nut holding the stud to the case. I reattached the two smaller wires with ring terminations to the stud as well as the two larger bundles of wires. I tightened up the nuts and the blower motors now work.
Thanks for the helpful suggestions from Rudy Leggitt and Roge Berke. A little help, being curious and wanting to understand how this complex combination of systems actually works goes a long way to feeling a bit more self-sufficient.
Roger
Try and switch the relays around. It may well be a bad relay.
We just left the Omaha area a couple of days ago and I know what you are talking about the roads being rough. We are headed back to Fl by way of the Brunswick Ga rally. Glad to be getting out of the cold and snow that we had while there. I am looking forward to nice warm Fl. : ^.^d )
I did check the relays. They were not the issue. It was the open ground circuits.
Roger