Thermostat Control Positions

Furnace, air conditioning, thermostats, distribution.
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Safaritoonces
Posts: 175
Joined: Sat Nov 02, 2019 9:51 am
Location: Bowen Island, BC
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Thermostat Control Positions

Post by Safaritoonces »

I have the Duo Therm AC & Hurricane heater control thermostat. I have replaced it with two LCD panels, one for each function heating and cooling. I used two because of technical reasons and they were ones I had on hand. Eventally they will be changed for a single unit now that I have them working correctly.

Here is my question. How does the original system work? There is a High/Low switch and a separate switch automatic position for the fans. If the switch is on low or high and automatic do the fans come on and off automatically until the temperature is correct? If on low for example does the fans run continously?

In the bedroom and shower area there are switches that say Heater On and Off. I don't understand this. What purpose does this serve because there is an on/off position on the thermo stat?[
Duo Therm Thermostat
Duo Therm Thermostat
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Robert and Bev Lewis
2000 Safari Continental, since 2017
3126B Cat, 330hp
MD3060 Allison
Bowen Island, BC

https://safaritoonces.org/

Jeffjordan1972
Posts: 2
Joined: Sun Oct 27, 2019 3:47 pm

Re: Thermostat Control Positions

Post by Jeffjordan1972 »

Robert,
The hi lo is fan speed on the AC unit. Auto means the fan only runs when the Thermostat calls for the ac compressor to kick in. On means the fan runs all the time.

Regarding the heater on off switches for your hurricane, I believe they turn the radiator/heat exchanger fans on and off in those zones. The hurricane gets “told” when to fire by the Dometic thermostat calling for heat and it will also cause the fans in the radiators/heat exchanger to come on but if you do not have those switches turned on they will not blow air across the heat exchanger/radiator. This could be useful if you wanted to, for example, use the hurricane to heat your domestic hot water without heating up the cabin further. Or if you want the hurricane to get up to temperature before you start moving air around so you’ll feel less chilly.

Safaritoonces
Posts: 175
Joined: Sat Nov 02, 2019 9:51 am
Location: Bowen Island, BC
Contact:

Re: Thermostat Control Positions

Post by Safaritoonces »

This now makes sense. The auto switch applies to the AC only. The low and high is for the AC fan speed only, with the heater speed control for the heater fans being the two separate controls.

This will make it easier to wire the controllers.

It was a slightly bizarre way of doing things, but I think they were trying to use the same temperature sense circuit and controller to regulate two separate devices.

I will post the project when it is done. Thank you for the explaination.
Robert and Bev Lewis
2000 Safari Continental, since 2017
3126B Cat, 330hp
MD3060 Allison
Bowen Island, BC

https://safaritoonces.org/

Safaritoonces
Posts: 175
Joined: Sat Nov 02, 2019 9:51 am
Location: Bowen Island, BC
Contact:

Re: Thermostat Control Positions

Post by Safaritoonces »

In the bedroom and shower area there is a high/off/low switch I understand now controls the heater fans in these two areas. In the control center cabinet in the kitchen next to the fridge, that has the tank levels, there is an heat on/off switch below the hurricane on/off switch. Is this the fan speed for the salon and kitchen areas? I have the controls apart right now so I can't test them.
Robert and Bev Lewis
2000 Safari Continental, since 2017
3126B Cat, 330hp
MD3060 Allison
Bowen Island, BC

https://safaritoonces.org/

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