Dometic AC/Heat Pump

[Johnny Mo]

I replaced 2 of the 3 Dometic 15000 AC's. Only One of the three was bad, so I replaced the 2 that share the same thermostat along with a new t-stat.

So I have 1 good and 1 bad unit along with a 5 button thermostat for sale. $200.00

Will not ship, I live So Cal

[vito.a]

I'm interested if your Aqua Hot still works in all 3 zones?

Thanks

[Johnny Mo]

Vito, I don't quite understand your Aqua Hot question.

But yes, My AH works fine...

[Tom Cherry]

17 hours ago, vito.a said:

I'm interested if your Aqua Hot still works in all 3 zones?

Thanks

Vito,

in order to have the Aquahot  work in all three zones, you need to have the exact configuration or wiring as the original. In this topic, Johnny has a two thermostat or in reality, TWO “separated” systems.  One up Front  (Zone 1) Thermostat with a single unit and one rear Thermostat with two two units ( Bedroom zone 1 & Middle zone 2].  They are NOT a connected. Each zone on each thermostat has a control module with a pair of dry or no voltage thermostat leads.  In some units, 2008 for example Monaco added a fourth zone which was only a control module to a specific Aquahot zone. 

The Aquahot doesn’t know how many systems or thermostats.  All it knows in,  Johnny’s case, is there are  THREE thermostats wire pairs or legs.  Think of each pair or thermostat wires as a light switch connection.  There is no voltage on the thermostat leads from each zone’s control module leads.. When in the furnace mode, each control module calls for heat and makes or close a circuit on these leads to the Aquahot….like turning on a light switch.  When the temperature in that zone reaches the set point of the sensor in the thermostat or if there is a remote temperature sensor, the circuit opens or the light switch is turned off.

Johnny replaced the two rear units and they had control modules that work the same way, except they only communicate with the new CC2 thermostat. So the Aquahot does not see any difference….all it knows, in Johnny’s case, is that the each of the two pairs of thermostat wires are opening or closing.  The Aquahot still delivers heat to the rear bedroom and the middle zone.  The front zone has the original 5 button thermostat so that control module is still opening or closing a circuit for the front zone.

As I understand his post, he left the front or original 5 button system in place.. It still works.  The rear two units were replaced with new units.  They will not communicate with the old 5 button thermostat, so he installed the new CC2 thermostat.  The remote sensor in the middle unit is just a “switch” that turns on or off.  It is attached to the new control unit so when heat is required, the control unit in zone 2 opens or closes the circuit going to zone 2.

I think that is what you are asking….and I hope this answers it.

Johnny had to put in two new units for the in the rear as they only communicate with the new CC2 thermostat. However, they function the same way, as far as the Aquahot knows, since they open or close the thermostat leads or pair of wires just like the original control module.  The original system, up front, was left intact. Just like the original configuration, the front system and the rear system do not communicate nor were ever connected together.

Hope this helps.

 

 

[Frank McElroy]

8 hours ago, Johnny Mo said:

I replaced 2 of the 3 Dometic 15000 AC's. Only One of the three was bad, so I replaced the 2 that share the same thermostat along with a new t-stat.

So I have 1 good and 1 bad unit along with a 5 button thermostat for sale. $200.00

Will not ship, I live So Cal

John - good decision to replace both AC units that were on the same thermostat - and on your coach, as you said, you only had two AC units on that thermostat.  That way the new units are compatible with each other and also compatible with the new thermostat.  Connections to Aquahot would be plug and play too since aquahot would have been on both old zones.  I'm sure someone will pick up the old units just for the good AC unit to buy them time if one of their old existing ones is bad. 

Our coaches are all aging and there will come a time when in the long run it's best to replace all the AC units and upgrade the thermostat at the same time.  Or at a minimum all units that are on the same thermostat as you did.  (Older high end coaches usually have 2 thermostats typically with two zones each.) The "furnace" aquahot connections should work just fine if all the AC units and any "hidden" extra zone controllers are replaced with new control boards as well.