Dometic AC freezing up

[H2oclass1]

My Dometic AC keeps freezing up. The freeze sensor reads 74° all the time, so I replaced the sensor. The new sensor never goes below 73°. I don’t think it would be low on freon or the freeze sensor would indicate that. Any ideas on what I should do next?

[dougrainer]

I hope you are honest enough to report when you do find the problem. As I stated, I have NEVER--NEVER had a control board have a problem with freeze sensor. It is always the freeze sensor. In the past 25 years since Dometic came out with the electronic freeze sensor system, I have probably worked and FIXED in excess of 500 Dometic AC system controls. Doug

[H2oclass1]

I think it's the control box too. I'm going to go ahead an buy one. It's from Amazon prime so I can return it don'ts fix the problem. Fingers cross

[time2roll]

H2oclass1 wrote:
My problem is in the living room. The one in the bedroom works fine. I swapped the two stat and the problem is still in the living room. Therefore I'm certain the thermostat is not the problem.

I assume it is the control box. Have the control boxes been switched?

[H2oclass1]

I Swapped the freeze sensors. The problem did not swapped.

[H2oclass1]

Because it's not the thermostat.

[dougrainer]

Last, What is the reason you do not want to call Easy Air? Doug

[dougrainer]

H2oclass1 wrote:
My problem is in the living room. The one in the bedroom works fine. I swapped the two stat and the problem is still in the living room. Therefore I'm certain the thermostat is not the problem.

Swap the freeze sensors (front to Rear/Rear to front). Even tho you replaced the one. Let us know. According to your posted Model number it is NOT a HP, just a standard AC. Swapping should be fast. Doug

[H2oclass1]

My problem is in the living room. The one in the bedroom works fine. I swapped the two stat and the problem is still in the living room. Therefore I'm certain the thermostat is not the problem.

[time2roll]

H2oclass1 wrote:
Doug
I have seen the coils ice over.
I swapped the stats and the problem did not follow.
I only have the problem on 1 unit the other 1 is working fine.
Kenny

Do both read the same temperature in each position when swapped?

One was working, right?

[H2oclass1]

The EasyTouch RV 351 thermostat has an information screen. It displays "Inside Coil Sensor:73F".

[wa8yxm]

Ok some nits and observations
1L when the OP typed "Condenser" yes he made a mistake. For he also said "IN THE ICE" and there should never be ice on the condenser save perhaps in late january here in the great white north (And you won't care at that point you will be using the FURNACE)

Next The thermostat... NOT even a suspect. The T-Stat if wall mounted has absolutely NOTHIGN to do with the freeze sensor.. They don't even talk to each other.. They do both talk to the control board but differnet ears (Ports).

I do not know how the O/P is reading the frost sensor.. I'm not aware of any A/C control system that has a way to do that.. So I'm now asking. How are you reading the sensor?

A Multi-Meter can measure the resistance.. now the problem here is most Thermistor deices are Negative Temperature coefficient Devices.
This means as the heat goes up the resistance goes down (Standard resistors like the filiment in an incasdascant lamp as they heat up the resistance goes up.. Special carbon units and others used in electronics may be deisigned to NOT do this)

But not all Thermisistors are the same value.. If you are using the Temperature setting on a multi meter with a Thermistor other than one designed for that meter.. you may get wrong readings.

Read the device in a room that's 72 and then stick it in the freezer and read it see if the resistance or the indicated temp on the meter changes.

[dougrainer]

H2oclass1 wrote:
The EasyTouch RV 351 thermostat does read the freeze sensor. They call it Inside Coil Sensor. In there manual it says "Temperature of inside coil has dropped below 30°F (-1°C). The compressor will turn off and the fan will run until the inside coil sensor temperature reaches 54°F (12°C)."

That is what the THEIR manual states. BUT, since YOUR system is malfunctioning, I still state YOUR Tstat is the fault, NOT the Dometic controls. The original Dometic CT Tstat DOES NOT have Freeze sense capability, to sense or display Freeze sensor. It only has 3 wire control and all communication must come thru the 2 wires of the three. Now, are you POSITIVE the "Coil Temp sensor is NOT the condensor sensor for a Dometic HP? The Dometic HP DOES have an external condensor coil sensor for freeze up in HP mode. THAT sensor may be your problem and not the freeze sensor for the COOL mode evap. This sensor if defective WILL cause lack of compressor operation. THIS is why I tell you to call Easy Air. WHY will you not call easy air? Doug

[H2oclass1]

The EasyTouch RV 351 thermostat does read the freeze sensor. They call it Inside Coil Sensor. In there manual it says "Temperature of inside coil has dropped below 30°F (-1°C). The compressor will turn off and the fan will run until the inside coil sensor temperature reaches 54°F (12°C)."

[dougrainer]

Since I have no knowledge of the Easy tstat, I looked it up. ANY Dometic wall tstat NEVER had the capability of reading the freeze sensor temp. I checked all the Dometic Easy air replacements and NONE had a spot for Freeze sensor capability. So, You need to really call easy air and get help. Doug