2010 20qv rooftop air conditioner freezing up

[laurieann]

It runs fine at home when getting ready to go, but when we set up it's fine for a while but will freeze up when we're going to bed

[TURBS]

Are all your vents open?
Is the frost sensor still attached?


TURBS
08 duramax tuned n modded
2011 32bhok Sabre
2015 camping "27 nights"

[laurieann]

Will check that this weekend we left it up at Reelfoot Lake going to crafts around the lake

[Bama Rambler]

X2 on the freeze coil. I had a unit do that exact thing and come to find out the freeze coil wasn't attached to the evaporator. I placed the freeze coil where it should have been all along and it stopped freezing up.

I also found several leaks between the discharge and return that I sealed up with aluminum backed foam tape. Didn't have another problem with it from then on.

[robert.beck.7737]

I experienced a freezing AC on my 2011 XLR TH with the main AC. Technician replaced freeze/temperature sensor with no improvement. Changed out fan and motor. Still no improvement. Last resort, replaced AC unit with a new unit. New unit has the same specs, but has a smaller foot print on top. Very satisfied with new Dometic AC.

[TimVWulp]

Originally Posted by laurieann

It runs fine at home when getting ready to go, but when we set up it's fine for a while but will freeze up when we're going to bed

Hi have you washed out the air filter for the A/C? Low air flow caused by a dirty air filter will cause A/C to freeze up.

Hope this helps Tim

[robert.beck.7737]

As I previously stated, I ended up replacing the AC on my 2011 XLR TH. First tried replacing the freeze sensor, motor and fan and cleaning the cooling find. The apparent problem was low freon and sense RV AC systems are hermetically sealed, replacement was the only alternative. I don't know why they are sealed without a port to add freon.

[TimVWulp]

Originally Posted by robert.beck.7737

As I previously stated, I ended up replacing the AC on my 2011 XLR TH. First tried replacing the freeze sensor, motor and fan and cleaning the cooling find. The apparent problem was low freon and sense RV AC systems are hermetically sealed, replacement was the only alternative. I don't know why they are sealed without a port to add freon.

Hi number one reason is cost. Second is a very high possibility it will leak at the service valves.

Hope this helps Tim

[Wolverine 1945]

Originally Posted by TimVWulp

Hi number one reason is cost. Second is a very high possibility it will leak at the service valves.

Hope this helps Tim

Are you sure a AC Tec could not add service valve ???

[TimVWulp]

Originally Posted by Wolverine 1945

Are you sure a AC Tec could not add service valve ???

Yes a service tech can add a service valve to the system to recharge the unit. Again it is cost at $80.00 - 100.00 / hr service time. One hr to prep and install the service valve, one to two hr to leak check the unit. one hr to recover the refrigerant from the unit and deposes of. One hr to prep and silver solder leak. two hour to evacuate the air from the unit. One hour to recharge unit with refrigerant and put covers back on unit. So now the A/C is running $500 - $800 have been spent in repairs. You still have an old used unit that may work for many years or die the next day. New unit costs is $800 - $1000 and you have a one year warranty on the new unit. If the repairs are going to cost 3/4 of the cost of a new unit buy the new unit.

Hope this helps Tim

[TURBS]

Price of adding ports exceeds the value of the a/c .

TURBS
08 duramax tuned n modded
2011 32bhok Sabre
2015 camping "27 nights"

[Wolverine 1945]

Originally Posted by TimVWulp

Yes a service tech can add a service valve to the system to recharge the unit. Again it is cost at $80.00 - 100.00 / hr service time. One hr to prep and install the service valve, one to two hr to leak check the unit. one hr to recover the refrigerant from the unit and deposes of. One hr to prep and silver solder leak. two hour to evacuate the air from the unit. One hour to recharge unit with refrigerant and put covers back on unit. So now the A/C is running $500 - $800 have been spent in repairs. You still have an old used unit that may work for many years or die the next day. New unit costs is $800 - $1000 and you have a one year warranty on the new unit. If the repairs are going to cost 3/4 of the cost of a new unit buy the new unit.

Hope this helps Tim

Sorry you lost me !!!
Are you saying it would take 5 to 8 hours to install a service valve ???
Hope I never run into your AC Tec !!!

[Bama Rambler]

If you read his post again, he plainly says it'll take an hour to prep and install the service valve, which is probably a good estimation.

He may be a little on the high side on everything except the leak check. That could take anywhere from a few minutes to many hours, and in some cases you may never find it.

[Wolverine 1945]

Originally Posted by Bama Rambler

If you read his post again, he plainly says it'll take an hour to prep and install the service valve, which is probably a good estimation.

He may be a little on the high side on everything except the leak check. That could take anywhere from a few minutes to many hours, and in some cases you may never find it.

I do understand the May Never Find It !!!
That is why so many Line Sets get replaced in homes !!!

[laurieann]

Had to throw the breaker this weekend it try's to run compressor with the thermostat in the off position help!

[TimVWulp]

Originally Posted by laurieann

Had to throw the breaker this weekend it try's to run compressor with the thermostat in the off position help!

Hi I need more information? Was the breaker tripped or did you have to turn it off and back on to reset the controls? Is the A/C running with the T stat in the off position? more information

Tim

[GL1800Rider]

Our A/C was doing the same thing. It never seemed to cool very well (purchased 6/15) when camping. Last trip it was blowing chunks of ice when I turned the thermostat up and fan on continuous and also was spitting water. Dealer checked it and said freon was leaking. Unit has been replaced and I hope to pick it up this week. I don't think these Dometic units are as good as the old Coleman Mach. The one on our 99 Terry still worked when I sold it this past spring.

[laurieann]

Originally Posted by TimVWulp

Hi I need more information? Was the breaker tripped or did you have to turn it off and back on to reset the controls? Is the A/C running with the T stat in the off position? more information

Tim

Had to turn off the breaker and yes compressor ran with T stat off

[TimVWulp]

Originally Posted by laurieann

Had to turn off the breaker and yes compressor ran with T stat off

The following chart shows the different electrical connections made by the thermostat during
operation. The chart below assumes12VDC(+) is supplied to thermostat Red wire “R” and that
12VDC(-) or ground is supplied to the Blue wire “B” at all times.
Thermostat Operations Internal 12VDC(+) Connections Made
Cool Mode Selected On Low Fan Red “R” to Yellow “Y” and Gray “GL”
Cool Mode Selected On High Fan Red “R” to Yellow “Y” and Green “GH”
Heat Mode Selected On Any Fan Speed
(Note: Furnace blower operates independently
from sequencer or time delay in furnace)
Red “R” to White “W”
Fan Only Selected (Hi-Fan Only) Red “R” to Green “GH”
Note: When the auto cool mode is selected on the thermostat the fan cycles “on” and “off” with the
compressor as needed. When the on cool mode has been selected the fan runs continuously and the
compressor cycles “on” and “off” as needed.
The following chart depicts thermostat wiring and the wiring destinations for air conditioners with
control boxes containing Printed Circuit Boards.
THERMOSTAT
TERMINAL /
WIRE
CONTROL AND SUPPLY
WIRING (OEM / VENDOR)
CEILING ASSEMBLY
TERMINAL
DESIGNATION
R or RED ONE RED, (+) 12VDC SUPPLY
WIRE TO THE THERMOSTAT
N /A
B or BLUE TWO BLUE, ONE (-) 12VDC SUPPLY WIRE
TO THE THERMOSTAT AND ONE BLUE
WIRE TO CEILING ASSEMBLY / PLENUM
B
Y or YELLOW ONE YELLOW, COMPRESSOR CONTROL
WIRE TO CEILING ASSEMBLY / PLENUM
Y
GH or GREEN ONE GREEN, HIGH FAN CONTROL WIRE
TO CEILING ASSEMBLY / PLENUM
GH
GL or GRAY ONE GRAY, LOW FAN CONTROL WIRE
TO CEILING ASSEMBLY / PLENUM
GL
W or WHITE ONE WHITE, 12VDC (+) FURNACE
CONTROL WIRE FROM THE
THERMOSTAT
FURNACE
NOTE: The (W) White wire is not available on COOL ONLY thermostats.
NOTE: THE CONNECTING WIRES TO THE THERMOSTAT ARE PROVIDED BY THE

The t Stat may be shorted or the wires behind the T stat may be shorted out. remove the t stat from the wall and reset the beaker. If it starts it may be the t stat. remove the yellow wire from t stat and see if A/C stops. If not problem may be the wires to the A/C or the A/C its self has a wiring problem.

Hope this helps Tim

[laurieann]

We had a wire not tight in stat thanks all