Dometic AC E4 Code.

[RickV]

Just went out to the pole barn to get something outta the 5ver. All the lights were off so I turned on the IN-Command Pad there was an "Dometic E4 Code displayed. I did a search and it says that the code is the Defrost circuit wire is loose. It said that it is a 2 wire connector on the control board at the front of AC. I searched for a video just to make sure I would do it right couldn't find one that showed how. Is there any trick or is it straight forward.

[ChuckS]

E4 error on your Dometic NXT HP AC unit is -- Freeze Sensor

I would first do a reset of your In Command ( HARD reset ) by turning shore power off and removing battery power

If E4 error is still present on Display then go on the roof and remove the outer cover on the Zone 1 roof AC unit...

Then remove the styrofoam cover and locate freeze sensor as shown in my second pic..

Verify its in position as shown

Then located the two wire plug on the AC controil box and remove and reinstall this plug ( this cleans the connection )

Now leave cover off and turn battery power on and then shore power and evaluate...

If issue is resolved reinstall previously removed covers

[ChuckS]

Hope your E4 issue is resolved

[RickV]

Originally Posted by ChuckS

Hope your E4 issue is resolved

Thanks for the info I was busy all day yesterday didn't get a chance to check it out, hopefully I can get around to it today. Something I didn't mention in my OP, not sure that it matters but the AC has been off since we brought it home from our summer place in WNC about 3 weeks ago.

[ChuckS]

Originally Posted by RickV

Thanks for the info I was busy all day yesterday didn't get a chance to check it out, hopefully I can get around to it today. Something I didn't mention in my OP, not sure that it matters but the AC has been off since we brought it home from our summer place in WNC about 3 weeks ago.

** Then I would do the Hard Reset on In COmmand before anything else.. the freeze sensor didnt fall out of the evap coils since the RV was just sitting there not moving..

If hard reset doesnt resolve ( a soft reset Will Not work ) the issue then take cover off and locate other end of freeze sensor wire plug and remove and clean it and reinstall.. then Hard Reboot again...

Your unit has the NXT Blizzard AC units and each have a gateway box that interfaces with the AC control box..

Locate the freeze sensor two wire plug on that gateway box ( found down inside evap coil duct up on top ) and clean that plug and reinstall.. The relays in the gateway may be stuck so thats why you wanna do a hard reset first

[RickV]

Chuck, I finally got a chance to do almost everything you suggested about an hour ago. Once I did the Hard Reset the In-Command quit giving me the E4 error. I still went up on the roof and checked the Freeze Sensor it was just laying there it was not connected to the the evaporator. I reconnected it where it looked like it fell out of and put a small piece of HVAC tape on it to help keep it place. I didn't mess with opening electrical box after seeing the wire loose.

Thanks again for your help and info.

[ChuckS]

Glad you got the E4 error resolved. With the sensor nit in the EVAP coils you would have Ice Up issues …

The Hard Reset most likely cleared the E4 error..

Suggestion based on your pics… when you get time I would go up and remove the cover again on All roof AC units and take an air hose up with you and blow out all the left over wood shavings as seen in the pic ( if you didn’t already)..

I would also remove the return filters inside on the ceiling clean the filters ..

The tape should help hold the freeze sensor in position on the coils..

Excellent follow-up with good pics. Your post will help someone else down the road with the same issues you had

[chuckster57]

Originally Posted by ChuckS

Glad you got the E4 error resolved. With the sensor nit in the EVAP coils you would have Ice Up issues …

The Hard Reset most likely cleared the E4 error..

Suggestion based on your pics… when you get time I would go up and remove the cover again on All roof AC units and take an air hose up with you and blow out all the left over wood shavings as seen in the pic ( if you didn’t already)..

I would also remove the return filters inside on the ceiling clean the filters ..

The tape should help hold the freeze sensor in position on the coils..

Excellent follow-up with good pics. Your post will help someone else down the road with the same issues you had

I agree 100%.

[RickV]

Originally Posted by ChuckS

Glad you got the E4 error resolved. With the sensor nit in the EVAP coils you would have Ice Up issues …

The Hard Reset most likely cleared the E4 error..

Suggestion based on your pics… when you get time I would go up and remove the cover again on All roof AC units and take an air hose up with you and blow out all the left over wood shavings as seen in the pic ( if you didn’t already)..

I would also remove the return filters inside on the ceiling clean the filters ..

The tape should help hold the freeze sensor in position on the coils..

Excellent follow-up with good pics. Your post will help someone else down the road with the same issues you had

I did after seeing that crap.

Thinking back that sensor must have been loose from day one. That AC would work good for a while then short cycle and would not be as cold. I suspect that the evaporator was iced up. The Bedroom AC never had that issue.

[ChuckS]

Also with that year Alpine and any 2020 - 2022 Alpine if you have not yet removed the entire roof AC unit and fixed what you will find underneath those units will never perform correctly

Every Alpine owner that has removed the units on the year groups mentioned has found exactly what you will see in my video

The Alpines made from 2010 thru 2019 were not like what is shown in my video

https://youtu.be/-QJTxSDZRWE?si=evJEgVe0KLYW1swb

This is an easy task to accomplish as shown in the video.. place a blanket or a few towels on the TPO roof membrane and then simply sit the entire AC unit on the towels to prevent putting a cut or hose in the membrane while fixing the mess you find under the AC unit

[RickV]

I have seen you post this before. I had my rig sitting outside the Pole Barn since last Saturday morning to clear the barn for our annual Christmas Party and like I posted I just got around to fixing the Freeze Sensor yesterday and then hooked up and put it back in the Barn . I have less then 1.5' of clearance in the barn so I'll have to wait until I pull it out of the barn again to do the modification.
One thing I have thought about doing was putting a Mini Split AC in it. Need to make some phone calls to find out if I can use some flexible hoses at the compressor unit because I want to mount that in the back but have a big storage area back there. My plan (if it can work that way) is to mount the compressor to a swing arm so once I am set up can swing the compressor out of the way of the door to the storage area.

[ChuckS]

That Mini Split is a nice setup.. I've seen several installs on Alpines ( not with storage door in the back ) that looked really nice and perform great..

If you can get the flexible hoses so you can swing out to access your rear storage compartment that will be one nice setup for you folks