Forum Discussion

dpgllg's avatar
dpgllg
Explorer
Jul 08, 2019

Domectic AC Freeze control sensor issue

Hello,

This past weekend our Dometic AC kept freezing up. We would let it thaw and it would freeze up yet again in hours.

I called a local RV shop and they said it was low on Freon and had to be replaced. No other possible issues could cause it.

My warranty expired on June 14th. I then called my dealer (over 3 hours away) and they also told me that IF it was a Freon leak the only solution was to replace. He stated that it could be other things as well such as the air mixing (hot & cold) because the divider was damaged. He suggested that I call Dometic and see if they could help in anyway. He also stated there was a 4 week or more wait to get into the shop.

I called Dometic and they were very helpful. I explained the situation and the lady told me that since it didn't freeze up in less than an hour that it most likely was not low on Freon. She also informed me that they would extend my warranty for this issue. I explained that the shops 4 week minimum wait. She stated that make the appointment and they would extend the warranty through that date. KUDOS TO DOMETIC!
I just had to provide the model and serial numbers to them.

I went over to the RV and opened up the AC from the inside to access the data tag. When I did a wire with a yellow tag fell down. It was the Freeze Control Sensor. Apparently the end is supposed to be inserted one inch into the evaporator coil fins. I looked up a replacement wire and it has a flat tab on the end inserted into the coils. Mine does not so I'm guessing that the wire became disconnected somehow.



My questions:
How does this sensor keep the AC from freezing up? Is there a defrost type of device that it controls? I guess what I'm looking for is what exactly does this sensor do and how does it work?

Since the current wire does not seem to be complete I will order a replacement as the cost is only $20 to $26.

How difficult is it to replace the entire wire? Where on the coils should it be inserted? The tag only states insert one inch into the coils.

Since the wire was not connected to the coils am I safe in assuming that this is the problem? Should I make the appointment to take it to the dealer in four weeks and then go ahead and replace the wire while waiting?

Thanks in advance for your comments!

Dave
  • When the Freeze Thermister senses freezing coil temp it shuts down the compressor. When the coil temp rises, the compressor comes back on. Doug
  • shastagary wrote:
    this should show how to install the freeze sensor Insert the Freeze Control Sensor


    Thank you for the link. I have printed the manual and will keeping it with the RV.

    It does not look to difficult and the new sensor will be here Thursday.

    Thanks again

    Dave
  • dpgllg wrote:
    Hello,

    This past weekend our Dometic AC kept freezing up. We would let it thaw and it would freeze up yet again in hours.

    I called a local RV shop and they said it was low on Freon and had to be replaced. No other possible issues could cause it.

    My warranty expired on June 14th. I then called my dealer (over 3 hours away) and they also told me that IF it was a Freon leak the only solution was to replace. He stated that it could be other things as well such as the air mixing (hot & cold) because the divider was damaged. He suggested that I call Dometic and see if they could help in anyway. He also stated there was a 4 week or more wait to get into the shop.

    I called Dometic and they were very helpful. I explained the situation and the lady told me that since it didn't freeze up in less than an hour that it most likely was not low on Freon. She also informed me that they would extend my warranty for this issue. I explained that the shops 4 week minimum wait. She stated that make the appointment and they would extend the warranty through that date. KUDOS TO DOMETIC!
    I just had to provide the model and serial numbers to them.

    I went over to the RV and opened up the AC from the inside to access the data tag. When I did a wire with a yellow tag fell down. It was the Freeze Control Sensor. Apparently the end is supposed to be inserted one inch into the evaporator coil fins. I looked up a replacement wire and it has a flat tab on the end inserted into the coils. Mine does not so I'm guessing that the wire became disconnected somehow.



    My questions:
    How does this sensor keep the AC from freezing up? Is there a defrost type of device that it controls? I guess what I'm looking for is what exactly does this sensor do and how does it work?

    Since the current wire does not seem to be complete I will order a replacement as the cost is only $20 to $26.

    How difficult is it to replace the entire wire? Where on the coils should it be inserted? The tag only states insert one inch into the coils.

    Since the wire was not connected to the coils am I safe in assuming that this is the problem? Should I make the appointment to take it to the dealer in four weeks and then go ahead and replace the wire while waiting?

    Thanks in advance for your comments!

    Dave

    If there isn't any "cancellation fee" for your RV shop, make the appointment and order the part(s). There's probably someone at Dometic that can walk you through replacing the wire, if you call them back. Or there may be a youtube vid or blog out there that demonstrates the procedure. If it fixes the problem, cancel the appointment.
    Cheaper than a shop visit?

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,189 PostsLatest Activity: Jan 21, 2025