2007 Dynasty CCC2 or Aquahot Issues. Changed AH board...not Thermostat does not work. Help

[Edward]

I recently purchased a new heat exchanger for the Aquahot heat system for the bedroom of my 2007 Monaco Dynasty. The rear CCC2 thermostat would control the Aquahot with no issues before but after I installed the new heat exchanger and restarting the system, I get no control of the Aquahot zone when I raise or lower the temp setting. The thermostat will control all other functions correctly but won’t see the Aquahot. I tried resetting the thermostat and even swapping the forward CCC2 with the rear CCC2 but neither would work when swapped. There was nothing I found online or in my CCC2 manual that really address this issue. Obviously I changed something or some other glitch appeared simultaneously while working on the system. What am I missing? Thanks for any insight or assistance anyone could provide.

[Dr4Film]

The CCC2 is seeing the Bedroom AH zone as stated in your post but the heat exchanger does not come on, is that correct?

if so then I would try putting the old one back to see what happens, first, then troubeshoot from there.

It could very well be a problem with the new heat exchanger.

[Edward]

Well the old heat exchanger has a leak so that why I replaced it. The fans tested good when I hooked up the 12v power to them. Zone 1 is indicated in Aquahot mode but when I raise the set point above the current indicated temperature to call for heat, the recirc pump and fans are not energized. The heat exchanger has no direct connection to the thermostat or Aquahot logic circuitry other than the 12v fan circuit. It is strictly a fluid component for the heated water source. I plan on doing more troubleshooting this weekend. I did do the burner cleanup , fuel filter, and burner nozzle during this same period so perhaps I failed to reconnect all wiring properly when I had it apart. The front thermostat controls Zone 2 & 3 properly so I know the control logic is working on the Aquahot. 

[vito.a]

The CCC2 thermostat controls the Aqua Hot through the A/C control board, and then through the 2 blue wires connected under the A/C unit. It will turn on the Aqua Hot heat exchanger fans regardless of the status of your boiler. 

First, I would clean the RJ11 (telephone cord) connectors on the back of the thermostat and also under the A/C unit where they connect to an RJ11 junction connector.  Many time this junction connector is the culprit so if you have another one just replace it.  Then I would perform a thermostat reset.  

When you drop the air filter under your zone 1 A/C also check the 2 blue wires from the A/C are still connected with no corrosion.  The two wires they connect to are not polarized so they can even be reversed and operate correctly.    

If you still haven't fixed it, you will need to go to the Aqua Hot wire connections and start checking the wires for zone 1.  They connect to a junction connector on the Aqua Hot firewall.  You'll need to look at your Aqua Hot manual to figure out with set of wires is zone 1.   

Good luck! 

[Edward]

I will double check the thermostat wires as I did take off the RJ11 connection when I swapped thermostats. I did a CCC2 reset with no change. The thermostat will control all other functions such as A/C and heat pump, just not the Aqua Hot. I verified the pump wiring is connected but will check the other Aqua Hot connections as I had a few apart when I installed the new fuel nozzle. I plan to swapped wiring between pumps to make sure pump is still operational. Just bizarre that it stopped working after replacing bedroom heat exchanger. 

[Tom Cherry]

First.....read and LOOK at this topic.  It is similar

NEXT....look at the print below.

The Aquahot control board has NOTHING....NADA to do with the Thermostat's ability to SEE or find or work the FURNACE.  If that function or mode is NOT SHOWING UP....then the problem is in the DOMETIC CCC2 and the ZONE...

SO HERE IS THE DEAL...

FIRST...  Can you SEE or do you HAVE A FURNACE MODE on Zone 1 in the rear.  I suggest that you do a RESET of the CCC2 Thermostat.  If you swapped out the controller and did NOT do any reset....THAT WILL IMPACT IT.  FORTUNATELY....your ZONE 1 in the FRONT and REAR are the same... here are the correct settings for each AC's Control Board.

Rear ZONE 1 or Bedroom.  HEAT PUMP (#7)...ASSUMING THAT YOUR HVAC IS A HP UNIT....must be on.  If it is AC ONLY...then DIP #7 is OFF...THEN FURNACE (#8) DIP is ON.  NO OTHERS.  By DEFAULT....when NO ZONE (2, 3, or 4) is selected....the THERMOSTAT then defaults to ZONE 1.  CHECK the SETTINGS.  VERIFY that the DIPS on the Bedroom AC are set this way.

NOW....do ZONE 2 or the MIDDLE.

ZONE 2 DIP is ON.  HEAT PUMP (assuming this is a HP unit) #7 should be ON.  IF NOT A HP....#7 is OFF.  FURNACE (#8) is ON.  

The FRONT system....since it is ZONE 1 MUST be the same.  

NOW....here in lies the problem.  You MUST reset (in the manual) EACH CCC2 Thermostat.  If you can NOT see or do not have or can NOT move the TEMP UP OR DOWN.  This is a DOMETIC ISSUE.  HAS NOTHING TO DO WITH AH....

UNLESS you MISSWIRED the NEW AQUAHOT.  There are TWO WIRES (pull the Penguin II install instructions.  They are only SWITCH CONTACTS.  NOW, if you have miswired or the control board is bad.....then....  I DO NOT KNOW.

Aquahot ZONE 1....this is COINCIDENTAL....and NOT anything to do with the fact that the DOMETIC Zone 1 is controlling the Aquahot.  NOW....FWIW....look at the FRONT thermostat....Follow the line or the wires from it.  that goes to ZONE 5 of the Aquahot.  SO...the AH Zones are THEIR numbers....and the Dometic Zones are THEIRS and there is not interface or any logic nor any "matching".  These are two separate systems.

What HAPPENS....when you are in the FURNACE MODE....and the Thermostat is set to say 75 dF and the actual temperature is say 70, the Thermostat sends a coded DIGITAL signal to the CCC2 Controller for that ZONE.  THEN the CCC2 Controller will CLOSE a set of contacts.  These contacts are the WIRES going from the CONTROLLER to the Aquahot ZONE.  There is NO POWER or VOLTAGE on the two lines.  Think as the Controller as a SWITCH....it closes.  The AH is looking for a CONTACT CLOSURE.

You can TEST the NEW AH board.  Remove the THERMOSTAT Wires from the terminals....THERMO + and -.  Use a paperclip.  jumper the terminals.  The REAR bedroom blowers should start and the Zone 1 Pump should start.  That is basically what the Dometic is doing.  This works on the Monaco Atwood furnaces as well....so changing out the board or controller should NOT have impacted the CCC2 System.

If you have LOST the FURNACE mode or if the Temp setting does not work....there is either a COMMUNICATION or Data Cable issue or you have a BAD CCC2 Controller or Thermostat.

The ONLY WAY TO TEST.....swap the Thermostat.  BUT YOU MUST then reset.  You can go inside the HVAC Plenum and unplug the data cables.  THEN remove the connector and hook up the Thermostat directly.  THEN do the reset.  All you will see is ZONE 1, but the modes like AUTO, COOL, HEAT PUMP (assuming it is a HP) and FURNACE modes will display and you can then change temps and such.

Folks have had to swap the thermostats and test them at the unit.....and found data cable (RJ11 issues) and had to Reterminate.  They have had to clean and clean the RJ11 ends  or replace them.

That's how it work.  

Lets HOPE that your AH Zone 1 works....by Jumpering.  If it does NOT....then maybe you reversed the FAN wires and the THERMOSTAT wires...  I can't say...

Look at the PRINT.  Notice the contacts for the AH zone for the BEDROOM.  

2007 Sig to Dynasty 5 Button AQUAHOT HVAC Layout.pdf

[Edward]

Zone 1 does show up when I select Aqua hot on the thermostat, it just doesn’t start pump #1 or fans on bedroom heat exchanger. I will double check my cables and try a reset again. The Zones can be a bit confusing between the CCC2 Zones and the AH zones…😳