Aqua Hot not heating

[smlranger]

We've never used the Aqua Hot system for anything but heating water since the only time we've needed heat the heat pumps did fine. So, in prepping the coach for a fall trip, I decided to see how well the AH heats the rig.

T-stat set for heat in the 'gas' mode, temp set 6 degrees higher than ambient in coach. Diesel burner switch on along with electric element.

Burner runs, I can hear the T-Stat click calling for heat, but I get no heat from any of the exchangers (one up front, one under galley, one at corner of bed). I do feel a tiny bit of heat from the exchanger under the galley. No fans running at any location.

I checked the AH and the two pumps were spinning and the outlet hoses were hot. I let it run for 20" and nothing changed.

So, burner is working, pumps seem to be moving the heated coolant but no heat or fans at exchangers.

Any ideas would be appreciated.

[Dupdyke]

My AH you set thermostats to furnace and fans to auto and all works just fine. I had a fan fail and put a new fan in with no big deal but can not believe all of them dont work sounds like settings issue. Burner switch will make burner and pumps run does not sound like it is asking for heat just hot water to me.

[smlranger]

Originally Posted by Dupdyke

My AH you set thermostats to furnace and fans to auto and all works just fine. I had a fan fail and put a new fan in with no big deal but can not believe all of them dont work sounds like settings issue. Burner switch will make burner and pumps run does not sound like it is asking for heat just hot water to me.

The AH 'Quick Guide' that came with this coach says set T-stat to Heat, use mode button to set mode to 'Gas' (my T-stats have no 'Furnace' in the display). I did that and I hear the t-stat click and I have checked that the two pumps (zone 1 and zone 2 pumps) are running and the discharge hoses coming off those pumps are hot. So the AH seems to be responding to the T-stat and pumping hot coolant out. My T-stat controls the AC and the heat pumps fine so not sure what to do at this point.

[JMonroe]

Sounds like everything is working except, the fans are not coming on. I doubt all the fans went bad at the same time, the solenoid or switch that controls them sounds like the most likely culprit.

I've found the Aqua-hot people helpful, maybe a call to them on Monday morning? Hopefully they'll have some ideas.

[kketterling]

Recommend setting thermostat to maximum temp to see if fans start. 6 degrees higher than temp in coach may not be enough to turn on fans.

[targaboat]

There may also be an upper temperature where the AH fans will not come on.

[Medico]

There are check valves just above the pumps as well. My Zone 3 works great, hot water works great, but Zone 1 blows cold air. Dealer recently replace Zone 1 pump, no fix. I contacted CC. Kevin contacted me and this is what he said:

1) Board supplies 12 v to pumps. If pumps don't turn suspect board.
2) Pumps can turn but not actually pump anything.
3) If board is good and pumps are running, only thing left must be Zone 1 check valve.

I now have a new check valve to install when it finally quits raining.

In your case this does not seem the same type failure. On my system there is a circuit breaker in the main circuit panel. I doubt this is the problem either.

Does the burner heat your water or is that not working either? Shut down the electric element and, if present, the optional hot water heater, and see if the burner heats the hot water.

Did you say you checked the fluid level in the reservoir?

[becks]

Gary...Are you aware of Roger Berke. He is the Aqua Hot go to guy. He has a forum you can join, and get tons of info. rvhydronicheaterrepair.com

[smlranger]

Thanks for all the suggestions. I believe I found the problem, a blown 20 amp 'heat exchangers' fuse in the fuse panel under the T-stat. So, replaced the 20 amp fuse and immediately I had warm air coming out the exchanger at the corner of the bed. I think there was also warm air coming out of the exchanger at the galley but not really sure since the new fuse quickly blew.

So, am now thinking one of the fans in one of the exchangers has a bad/shorted motor. Of course, it will be in whichever exchanger is most difficult to access (under the dash or in the water bay) .

Since I have an ESP that will cover this less my deductible, I will make an appointment at Tom Johnsons. I will let them bird dog the issue and do the contortions required to fix it.

[smlranger]

Originally Posted by becks

Gary...Are you aware of Roger Berke. He is the Aqua Hot go to guy. He has a forum you can join, and get tons of info. rvhydronicheaterrepair.com

Yes. I joined his forum and have ordered stuff from him. He suggested it was a bad check valve but I have good flow of hot coolant from the pumps.