[Trainer]

David, The clear relays you pictured control the zone pump and zone fan(s) for the Living Room, Bathroom and Bedroom. The bedroom relay is the bottom one. The fan connection to the relay is the top one on the pump side of the relay. Power for the fan is the top one on the other side facing you as you look at the heater. The power connection is one of the fuses above the relays. If any zone fan works the fan fuse is olay.

Hope this helps you.

[dbld58]

Thanks Rudy.

I'm struggling with this because the bathroom, galley, and driver fans all work.

The salon/living room heater is a toe-kick self contained electric cadet heater so it would not be a factor.

I'll fiddle around with the AH relays some more. Does anyone have a diagram for the relay wire connections? I hoped to see some common wire colors at the fans and at the relays but I didn't. The wires feeding the fans are brown and blue if my memory serves me...I'll have to open that up again to verify.

[Richard]

I don’t know if this is a applicable to your coach. I can turn on the AH fan and heater in the rear bathroom with a twist style old school thermostat.

The bedroom AH fan is controlled by the combination air conditioning and heat control thermostat located in the bedroom.

So do you have a heating option for the AC controls in the bedroom?

Again, this may not apply to your rig at all.

[dbld58]

Hi Richard,

I have the old school thermostat in the rear and center bathroom for the heaters in those rooms respectively. Those are working.

My bedroom heater under the bed is activated by the thermostat in the galley as zone 3 furnace, and is the only one not working at the moment...it gets the hot water from the Aquahot, but not 12 volts to start the fans.

Strangely, the furnace for the galley operates from that same thermostat but under zone 1.

[Richard]

Copy that.

Look at your zone 3 to see if you are getting power on the terminal that is supposed to power the fan. I am not sure if this is the same model you have, but if you wade through to the wiring diagrams for the cozy heaters it may help you find the needle in the haystack.

https://library.aquahot.com/wp-content/u...l03-96.pdf

[Trainer]

David, the thermostats do not provide power to any pump or fan. They only ask for heat in a zone. Once the request is received down at the heater, a clear relay closes providing power to a pump via the bottom connection and to the fan(s) via the top connection.

If the bedroom coil is getting warm but no fan in the bedroom, get the vom meter set to vdc, 0-20 volts and check for power on the top connection on the bottom relay on the side facing the pumps. If no power there, pull one of the other relays and insert it in the bottom location.

If the fan does not start and power is present on the top connection, you have a fan problem. Your meter will tell you what to replace.

PM or email me your phone number and Saturday I will walk you through diagnosing the problem.

[bestgenman]

I’m going from memory here so there may be error in my old brain.
The AH terminal connections for zone A B &C are seeking a ground and Newell adds an automotive relay since the Dometic call for heat goes +12.  The automotive relay coil is connected to the Dometic furnace output and also to the old school stat and the contacts close taking zone A or B or C  to ground.  

Rudy is spot on, if you have heat on the piping to the coil then the pump is likely running and you should have a signal (+12) to the fan motor.  Check voltage at the motor.

At least that is how Whitey at Newell explained it to me.  Yours may be different.

[Richard]

Gordon,

Your memory and explanation are spot on.

The key point being, and I realize that I am repeating what you and Rudy said, that the relay is activated or the pump would not run. The next logical check is to put a voltmeter on terminals 4 and 6 to see if they have 12v. The fans are typically powered by either of these terminals as indicated by the manual in the link I posted.

If those terminals have 12v, then I would check the continuity between there and the terminals at the fan.

[2BirdDogs]

Thanks Richard.

I have some trouble shooting to do.  The baseboard/toe-kick vents in the salon and the bedroom aren't blowing hot air.  Actually, they aren't blowing at all so I am guessing I need to sort why the fans aren't turning on and then make sure the water is flowing. Everything else is working.

Any suggestions on where to look first?

In our coach I have to have the thermostat set to “gas heat” in the salon and bedroom for those AquaHot vents to blow heat. 

Paul

---

Thanks Richard.

I have some trouble shooting to do.  The baseboard/toe-kick vents in the salon and the bedroom aren't blowing hot air.  Actually, they aren't blowing at all so I am guessing I need to sort why the fans aren't turning on and then make sure the water is flowing. Everything else is working.

Any suggestions on where to look first?

In our coach I have to have the thermostat set to “gas heat” in the salon and bedroom for those AquaHot vents to blow heat. 

Paul

[dbld58]

Thanks all - I had to go to a family event all day yesterday and need to spend time at home today. I'll recheck everything tomorrow.

I very much appreciate all the info and effort.