Aqua Hot thermostat settings

[Larry Whitaker]

We've had RV's for over 35 years. In February, we purchased a 2006 Beaver and have been it fixing some and using it a lot. Wonderful coach. Our biggest headache is the thermostat control system. I finally figured out how to get ac for the summer but now can't seem to get the heat to work. We have the Aqua Hot system and and two Dometic CCC2 thermostats. I've read the manual, reset the thermostats, looked at lots of posts online and it is really baffling...and I'm not techno challenged either. After resetting, the front thermo says it's Zone 1 and the rear says it's zone 3. All we want to do is turn on the heat and set the temp or turn on the air and set the temp. We don't want to program any times. One time, I got heat in the front registers and cold in the rear registers but now I get no air at all out of them at all. Can you help?

[Michael Hannan]

It sounds like your system is similar if not the same as mine.  So I'll tell you about mine.

The front (living area) is zone 1 so what yours reads is correct.  The heat/cooling is controlled using the Mode button when the thermostat is turned on (small black switch on the bottom of the thermostat.  The topmost setting of the mode is off following by fan only. The speed of the fan can be controlled using the fan button on the right.  The next mode is Cool which is your AC which uses the Up & Down buttons to set the temperature. Next mode is Heat Pump which is heat from your AC/heat pump system.  Same as with AC the temp and fan speed are controlled by the buttons on the right.  Next mode is furnace.  This is the Aquahot part of your heat.  You have a couple of things to make sure of here.  The diesel switch on the panel to the left of the thermostat must be on and you'll have to check the floor level heat vents and any with a switch beside it needs to be switched to high or low to control the speed of the fan that blows air through the hot water exchangers.  That's it for the front.

The thermostat in the bedroom is much the same.  In zone 2 the Aquahot furnace heat is where you will find it.  Mine has a zone 3 available too but I don't use it so not sure what all it does.

Hope this helps.

MJ

[Larry Whitaker]

The bedroom thermostat only shows zone 3, there is no zone 2.

[Joel Ashley]

Larry, there probably is a zone 2, but consider it the bay heat exchanger and its automatic, non-adjustable thermostat that keeps your tanks and water utilities from freezing.

The original 2 living area thermostats for our '06 Monterey are Duo-therms.  I don't know which model coach you have, but I'm guessing someone may have switched thermostats along the way, perhaps when installing new roof airs.  I presume you are dealing with this:  http://www.campingworld.com/shopping/item/duotherm-a-c-5-button-comfort-control-center-new-style-/21759&utm_source=google&utm_medium=cpc&scid=scplp21759&sc_intid=21759?utm_campaign=SC_Shopping_Low&affiliateid=6338&gclid=EAIaIQobChMIyMep0_Hx1gIV3rjACh0LcwLMEAQYBCABEgLio_D_BwE

Not being familiar with that thermostat, I can't help;  but if you've followed the manual with no positive result, you might check the HydroHot/AquaHot control panel (on a bay wall with the unit) and see if there isn't a red fault light showing somewhere.  The issue may be with the hydronic control (assuming the burner and/or electric coil have been heating water for you) and not the thermostats. 

No air out of the exchangers implies perhaps a low battery fault somewhere in the past is blocking their activation, although others here understand AquaHots better than I.  There are helpful documents in the Club's Coach Assist section here.  Unlike Michael's, the hydronic switches in our coach are on the galley rail below the counter, not next to a thermostat.  Turning the diesel switch off for a minute and back on should reset the hydronic control and clear any fault as long as it's original cause has been rectified.

Also keep in mind the floor exchangers are blocked out whenever much hot water is called for somewhere, though you'd have noticed a hot water leak of that significance.  A previous owner may have set thermostat programs that are confounding you, but I presume your manual helped you delete them.  I'm glad our factory 'stats aren't that complicated;  I have enough trouble trying to get the generator's auto program to set right.

Joel

[Steve Huber Co-Admin]

Larry,
Please let us know what model coach and engine you have. It will be helpful in diagnosing problems.
Steve

[Larry Whitaker]

Thanks for all the replies to my post. We have a 2006 Monterrey Montclair IV. The thermostat is a CCC2 by Dometic.

[Stan Simpson]

It looks like "mode" might hold the answer, Larry. If you hit that button, is there an option to change? Like a/c, furnace, or heat pump?

[Larry Whitaker]

Yes, there is a mode. This morning, I set it on furnace and nothing else and the heat came on in the front of the coach. I did the same with the rear and the fan came on but only blows cold air.

[Joe Moreschi]

Hi Larry did you feel for heat in hose while it was blowing cold air? Maybe the valve is stuck closed.

[Larry Whitaker]

Joe, I didn't. Where is the hose?

[Bill Sprague]

Yes, there is a mode. This morning, I set it on furnace and nothing else and the heat came on in the front of the coach. I did the same with the rear and the fan came on but only blows cold air.

There are check valves next to or above the circulation pumps.  They commonly stick shut when not used for awhile.   Tapping on them with something like a screw drive handle often gets them unstuck. 

[Joel Ashley]

You may have to remove the floor register grate to see the hoses coming and going from the exchanger.  If you're lucky, just removing a drawer or cabinet floor above it is all that's necessary.  If the hoses aren't warm, like I suspect the one in your bedroom, then suspect that one's (zone 3) pump as Bill noted, specially since the exchanger's fan works - hot fluid just isn't getting pumped to it on demand like it should.

Joel