Heat and thermostat question

[Pwmcx95]

I just purchased a 2000 Tiffin Alegro Zephyr.
I am still trying find out how everything works. My question now concerns the heating and cooling system. I set the thermostat to "heat pump" and the gas furnaces come on. I switched to a/c and the a/c will not come on.
Also the thermostat shows zone 1 and I don't see how to change to different zones or is it automatic?
Doesn't make any difference is it is on generator power or shore power.
Any ideas or help.

Paul

[Bug512]

Just a shot here but what is the outside temperature?
I know on our Winnebago that if the (inside) temperature is more then 4 degrees away from the heating setpoint it will use the furnace first.

As far as the AC, maybe there is a ambient temperature lockout like on commercial systems ?

[Pwmcx95]

Acutally outside temp is 37 deg. You may be on to something.

wish I ahd a manual to explain all this.

Paul

["007"]

Maybe this link will explain things for you.
Welcome to irv2.

[Pwmcx95]

Before I look at the link you supplied, I just tried somethinh else.
I set the thermostat to fan only mode, the furnace kicked on.
Maybe I have a defective thermostat?

I will check out the link you sent.

Paul

[Pwmcx95]

I have an update, I found the info about adjusting the contacts in the thermostat switches. Did that and no change.
Next went to control boarod on front unit, checked fuse, not blown, unplugged power to board and reconnected. Could not see anything wrong.
went over to thermostat and tried to change modes, now I can change to mode 1, 2 or 3. Now my a/c units run in all three modes. I can control the furnaces in any mode now.
I have heatpump in mode 1 and mode 2. When I set thermostat to mode 3 and heatpump I never get any heat.
Is it possible rear unit (mode 3) is just a/c or do I have bad unit?
I have never owned a unit with 3 roof a/c's and 2 furnaces.
Anyone know how all this is supposed to work?

[Luckiest Dre]

I believe mine has mode 1,2, 3 for the roof air and you just scroll thru and set each to the wanted temp setting when there. But with only 2 furnaces when you scroll thru one of the settings is blank and you get no results when there. My furnaces are on 1 and 3.

[diveman52]

Just a guess but seems you have a Dometic comfort control system?
The older one seem to have problems with the thermostats. I know there's a couple of people who will fix them for about the coast of a new 5 button unit.
How ever the newer 5 button will not replace the older 4 button.
You can upgrade the whole system by buying two new control boxes for the AC unit and a new 5 button control thermostat. Should be able to find all for around $300.00 if you search and ask.
Oh yes heat pumps don't work below around 40 degrees so the turn the propane heater on instead.

[Pwmcx95]

Larry B,
My system is like yours. I only have furnace on xone 1 and 3.
The weather has been so cold I test to see which heat pumps acutally work. I know one day I did get heat from zone 1 and 2 heat pump, never could get heat from zone 3.
I have had to saat here at the shop last 2 nights, outside temp in low teens and the gas furnaces run good. I put a small ceramic heater in the bed room . That cause zone 3 temp to be up and furnace for zone 3 won't kick on.
Need some warmer weather to get all checked out good.

Paul

[Pwmcx95]

Diveman52,
If I change to the 5 btton system, don't I have more wires to run from circuit boards to and from circuit boards.
My 3 units have circuit boards in each.
I did clean contacts and reform contacts on 4 button switch to get control of each unit.
I think I am supposed to have heat pump in all 3 units but have never got heat from zone 3 in heat pump mode. So cold out side can't tell if a/c is even working.
How difficult a job is it to change to 5 button system with 3 units?

Paul

[diveman52]

No you don't have to change any wires. the Comfort control system uses telephone type wire (4 wires cable) with telephone style RJ11 jacks it's prety much plug and play. Just unplug existing cable install new contol boxes and thermostat, plug into new boxes and thermostat read instructions on set and go.