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ronbunge · 05-31-2023, 03:53 PM

Dou-Therm two zone system and zone 1 on AC cycles on and off even with temp set low and zone 2 will stay one and run OK. Will check the top unit for a dirty filter or coils. And then try thermostat reset. Any ideas on this issue? At this time only have 30 amp so can't run both top units at once. Next, if I can figure out the manual may try to switch zones to prove if one top unit is bad.

MrMark52 · 05-31-2023, 03:58 PM

Are you saying the fan runs continuous on one unit, but cycles with the compressor with the other unit?

If so, check the “Fan - Auto\On” switch setting -
“Auto” cycles the fan with the compressor (i.e. cooling)
“On” makes the fan run continuous while the compressor cycles.

ronbunge · 05-31-2023, 04:23 PM

With the generator on so can test both units zone 1 and 2 the front zone 1 still cycles on and off. Shore power is only 30 amps. Both the fan can condenser cycle in zone 1. Fan is on auto and the rear zone condenser and fan stay on when the front one cycles.

MrMark52 · 05-31-2023, 04:47 PM

Let me rephrase my previous comment - on the thermostat that does not cycle with the compressor -

Quote:

Originally Posted by MrMark52

If so, check the “Fan - Auto\On” switch setting -
“Auto” cycles the fan with the compressor (i.e. cooling)
“On” makes the fan run continuous while the compressor cycles.

On your thermostat(s) - there is the temperature control slider, a switch that says “Cool-OFF-Heat”, and a switch that says “Fan - Auto-On”.

If your thermostat(s) doesn’t/don’t indicate that described above, please advise.

ronbunge · 06-01-2023, 09:16 AM

I have the five-button controller and it is set to auto fan. When the front zone 1 unit cycles both the condenser and fan shut down. I have checked for debris in the coils up top and they are very clean.

MrMark52 · 06-01-2023, 10:09 AM

How many thermostats do you have?

My comments are made on the basis you have 1 thermostat for each unit.

If you only have 1 thermostat (which I doubt), and it is driving both AC units, then both AC units should act together.
Alternatively, it is possible you only have 1 wall mounted thermostat for the unit that is cycling, and the temperature control for the unit that is not cycling is on the unit itself.

If the alternative set up is your set up, then we’re gonna need a little more information.

vito.a · 06-01-2023, 10:28 AM

How old are the Dometic A/C units?
More than likely the zone one unit is low on refrigerant and short cycling. You can add a tap and add some refrigerant.
Or, you can replace the unit. The problem you will have is the new A/C units are not compatible with the older 5 button thermostat. You can install a retrofit control board in the new zone one or replace both A/C units along with a new thermostat.
Good luck!

ronbunge · 06-01-2023, 10:45 AM

I have on thermostat controller (5 button) and it has control for zone 1 and zone 2. Each zone can be set for its own temp.

MrMark52 · 06-01-2023, 12:25 PM

Quote:

Originally Posted by ronbunge

I have on thermostat controller (5 button) and it has control for zone 1 and zone 2. Each zone can be set for its own temp.

OK - then does the thermostat have an internal and remote air temperature sensor, or two remote sensors at each end of the coach, or is it just a single sensor?

Contrary to some advice given - the LAST thing you want to worry with is the refrigerant charge - unless you have climbed up on the roof and looked for signs of refrigerant leakage. 95% of the time, a refrigerant leak is evidenced by indications of oil, which show up as copper tubing that looks darker and semi-wet looking - the result of oil seeping out at the leak.

ronbunge · 06-02-2023, 09:01 AM

OK - then does the thermostat have an internal and remote air temperature sensor, or two remote sensors at each end of the coach, or is it just a single sensor?

Two remote sensors. Not worried about refrigerant as it is sealed and is blowing cold air.
Cecked the seals between the cold and hot air return and seen to be good as to not let cold between them. Just cycles on and off.

MrMark52 · 06-02-2023, 11:38 AM

Ok - I’m getting a better picture of what you have -

So, which unit do you feel is the problem unit - the one that cycles, or the one that runs all the time?

For the one that runs all the time, what is the temperature in the area where it’s sensor is relative to the set-point temperature on the thermostat?

Same thing for the one that cycles, when it cycles off, and when it cycles on? I’m suspect you may have a power wiring problem with that unit if it doesn’t reach set-point temp for the sensor of that unit.

shootist · 06-02-2023, 04:34 PM

What coach ? And do you have an aquahot?

ronbunge · 06-02-2023, 10:52 PM

So, which unit do you feel is the problem unit - the one that cycles, or the one that runs all the time?
The one that runs all the time is just fine, it is the one that cycles.

What coach? And do you have an aquahot?
Monaco 05 Caymon 37 PDQ NO aquahot.

MrMark52 · 06-03-2023, 08:11 AM

Quote:

Originally Posted by ronbunge

So, which unit do you feel is the problem unit - the one that cycles, or the one that runs all the time?
The one that runs all the time is just fine, it is the one that cycles.

What coach? And do you have an aquahot?
Monaco 05 Caymon 37 PDQ NO aquahot.

Ron - the one that cycles - has the temperature in the area reached the set-point temperature causing it to cycle?

And - has the temperature of the area for the other unit reached it’s set-point temperature, causing it to not cycle?

FWIW - to respond to posts - click the “Quote” button for the person you want to respond to, then in the message reply box, below where you see the message repeated (and ending with [/QUO**]), type in you message.
Doing this makes it easier to track your responses.

If you want to respond to multiple people in a single message - hit the “Multi+” button. Again, this makes your responses easier to follow/find.