Changing refrigerator cooling unit...New or Refurbished??

[SJ-Chris]

Summary: When replacing the cooling unit on your refrigerator, would you go with a refurbished unit ($450) or a new unit ($650)??

Here's the story...
I have a 2015 Thor Majestic 28a. The refrigerator is a Dometic DM2852RBX (8 cubic feet).

Recently it stopped cooling on either propane or electric. I tried all the troubleshooting things I could to no avail. The heating element is good (as I can feel the stack getting hot on either propane or electric).

So I took it to my RV repair shop. They diagnosed it saying the cooling unit was bad. They told me they recommend replacing the entire refrigerator (~$2200 for the new fridge which includes their 40% markup, plus ~$500 in labor).

I asked them how come they don't just replace the cooling unit. They said "they can't find parts for this particular unit". I spent 2 minutes googling and immediately found the parts (refurbished or new cooling units). I suspect replacing the entire refrigerator is a much higher profit for the repair shop which is why they recommended that (...thanks a lot, right??).

I've decided I'm going to fix it myself. I'm pretty handy. There are several youtube videos showing start to finish and it looks pretty straight forward. I pulled the refrigerator and layed it down on a blanket on my couch. Then I removed the existing cooling unit being careful to label everything and take lots of photos. It only took me 40 minutes to do so and it came out super clean which I was happy to see! I wanted to make sure I could remove it successfully without damaging the refrigerator unit BEFORE I order the new cooling unit (...figuring worst case if I couldn't get it out or if I broke something I could just buy a new refrigerator for ~$1600 and install it myself).

I'm going to order a replacement cooling unit. The online company sells REFURBISHED ones for ~$450. I'm told by the company that these will perform similar to the existing one that originally came with the refrigerator. OR, for ~$650 I could buy a brand new UPGRADED design that they say will have better performance and be able to keep the refrigerator colder especially when it happens to be 100 degrees outside. They also say it should last longer.

Do any of you have any experience or opinion as to how much better the NEW replacement unit might be over a refurbished unit (in terms of its ability to keep the refrigerator cold)?

Thanks in advance!
Chris

[wa8yxm]

-10 is "Deep Freeze" (anything less than zero) so you know.. Long long term storage.

To the question New or Refurb. I would (And did) go with a NEW Amish built cooling unit.

[SJ-Chris]

SJ-Chris wrote:

(Note: I have two identical RVs...2015 Thor Majestic 28as. If I have the time one of these days, I'll do a refrigerator test on the two RVs. One has the origianl Dometic cooling unit, and the other one now has this brand new Amish built cooling unit that is supposed to provide better performance. I guess that would be a good way to see the difference (if any))

It's been a while, but yesterday I "accidentally" did a comparison test between the OEM refrigerator/cooling unit and the Amish one. I am getting ready to go on a trip with multiple RVs and so I turned on the refrigerator on both of my 2015 Thor Majestic 28a Class C RVs. Daytime temps are about 65*F and nighttime about 40*F. When I checked on the two refrigerators in the morning to verify they were both working as expected, I got a little surprise...

On the OEM refrigerator/cooling unit, the refrigerator section was at 35*F and the freezer section was at 4*F.

On the refrigerator that I had installed the Amish cooling unit, the refrigerator section was at 34*F and the freezer section was at -10*F.

It was only then that I remembered the salesman tell me that the Amish cooling units "worked better than the OEM cooling units". I guess he was right afterall!

Stay cool!
Chris

[MrWizard]

Well done...great job

[Fisherman]

Nice work.

[SJ-Chris]

Wanted to give you all an update...
Note: This was the first time I had ever tinkered/fixed anything on an RV refrigerator. I do have a decent amount of other DIY experience though.

My refrigerator died. It was diagnosed to be a cooling unit failure.

I purchased a brand new Amish built cooling unit from www.RVcoolingunit.com $730 shipped.

Spoke with David who works there and he was GREAT with the info. He also send a link to their youtube video and also send a pdf explaining the process. It looked doable.

Since I was going through the hassle of changing the cooling unit, I figured I'd go ahead and replace the heating element (~$35) and also the thermister ($25) (which I think was bad).

I removed the refrigerator from the cabinet and layed it face down on my jackknife couch (which was covered with a thick blanket). I was able to remove the refrigerator and the old cooling unit in just 40 minutes. I was really surprised it was so easy, and that even included time to take photos every step of the way (so that I would be able to put it back together again) and also labeling everything and putting various parts into ziplocks with a postit note saying what it was. That came in handy when putting it back together.

Took a week to receive the shipped cooling unit. It was a little intimidating installing it...mostly because I had never done it before. I first did a test (without any of the thermal mastic or sealer) just to see if everything would fit. I would say it fit very close. It was off a little on the frame edge, but I hoped it would be within functional tolerances. Once I was convinced it was going to work, I removed it, put on the mastic and sealer, installed the refrigerator fins and put the cooling unit back on. It was a little bit of "leap of faith" because with the refrigerator laying face down at that point I wasn't 100% sure that all the screw holes of the freezer were going to line up when I had it upright again (...I had already attached the fins).

I fastened the cooling unit and then started putting all the controls and heating element back in their proper places. It was a little challenging as the holes on the new frame didn't match up everywhere on the previous frame (so I had to drill some new holes). Once I thought I had it all together, I tilted it upright and let it sit for over an hour (so all the internal liquid could settle). Thankfully, I was able to securely fasten the freezer screws through the back wall of the freezer into the cooling unit where they had a comfortingly snug fit. Phew!

Then I wanted to do a test BEFORE installing it back into the cabinet. I wanted to make sure it worked first, and I knew that if I had to make any adjustments/corrections on the back of the refrigerator, it was going to be a lot easier doing it while the refrigerator was out. I was going to first test it on 110v electric (not gas). I figured that would be easier, and also I had no way of testing it on propane until I put it back in the cabinet and hooked up the propane. So I plugged it in to 110v.I placed a digital thermometer in both the freezer and the refrigerator and the temps started out at 62 degrees. Clicked the "On" button and nothing happened. That's when I remembered....the refrigerator needs 12v for the controls EVEN IF it is running on 110v. So I ran 12v to the control board of the refrigerator and I turned on the refrigerator. This time, it lit up (phew....the first sign of life!).

Then, I waited.... I could eventually feel that the stack was getting hot over near the bottom where the heating element is. I had a brief scare when I saw a tiny bit of smoke. I wondered, "Is it all going to catch on fire?" Thankfully, after the tiny bit of smoke it stopped. Perhaps it was just burning off some of the newness of everything. The stack continued to get warmer. I took this as a good sign. I could feel inside the freezer against the back wall starting to get cold after just 15-20 minutes. During this time, I started putting the doors back on the front. The stack continued getting warmer over the next hour. Everything seemed to be working as expected. So I continued cleaning up wires, putting on thermal tape around the edges of the back of the refrigerator, etc.

It used to take about 2-3 hours for my freezer to get below 32 degrees F, and it would take the refrigerator probably 5-7 hours to get below 40 degrees F. BUT, the only time I've ever really paid attention to that is in the summer time where our usual temps are between 80-100 degrees outside. Today, our temps were about 65 degrees. Well, after about an hour and a half, my freezer was down to 10 degrees F and at about 2 or 2.5 hours my refrigerator was down to 33 degrees F. I considered that very fast and I was quite pleased. I was told that this brand new cooling unit (rather than a refurbished one) would have better cooling performance. So far, I'm VERY happy!

(Note: I have two identical RVs...2015 Thor Majestic 28as. If I have the time one of these days, I'll do a refrigerator test on the two RVs. One has the origianl Dometic cooling unit, and the other one now has this brand new Amish built cooling unit that is supposed to provide better performance. I guess that would be a good way to see the difference (if any))

So it was time to put the refrigerator back into the cabinet and hook up the gas and give that a try. I had my son help me put it in the cabinet and it slid right in. I hooked up the gas line and then did a bubble test to make sure it wasn't leaking any gas. Then it was time to try it on gas. Fingers crossed....... I switched over to gas, I heard the igniter click, click, click, click, click, click...and then that beautiful "whoooosh" sound of the gas igniting! Music to my ears. I watched it for a bit and everything looked like it was doing what it was supposed to be doing. I finished putting everything back together and securing everything as it was supposed to be.

40 minutes to remove the refrigerator and the old cooling unit.
~3 hours to install the new cooling unit and get it back into the cabinet. (there was about 2 additional hours during the install process where I was testing/waiting to see if it was working, checking on it every 15 minutes or so). In total, it was probably about 4 hours of work. Not bad for having never known a thing about how a refrigerator work before this repair. My mechanic shop wanted about $2400 to replace the cooling unit so I ended up saving about $1500 which is nice. Plus...I learned a lot about refrigerators at the same time which could come in handy later (...I own a couple RVs).

I parked it back into storage this evening and I put the refrigerator on propane to try that overnight. I'll check on it in the morning. If I have any surprises I'll post another update.
(Update: I check on the fridge in the morning and the refrigerator was holding at 34 degrees and the freezer was 7 degrees F. Stayed there all day. Looks like the fridge is at 100% once again!)

Thanks to all of you for the amazing help, suggestions, etc. I appreciate this forum and all the helpful guidance. I'll be sure to return the favor anytime I see a place where I can contribute to help others.

-Chris

[MrWizard]

If needed, I would buy new, been burned already
On local rebuild/refurbished cooling unit

[Old-Biscuit]

Boon Docker wrote:
OP stated:

"Recently it stopped cooling on either propane or electric"
"The heating element is good (as I can feel the stack getting hot on either propane or electric)."

So yes, it seems pretty obvious.
Unless both heating element and propane system quit working properly at exactly the same time or the flue just suddenly is in need of cleaning. 😉

Just saying....
Nothing is obvious unless signs of leaking is evident

5 yr old fridge.....
One should TEST before ASSUMING

[Boon_Docker]

OP stated:

"Recently it stopped cooling on either propane or electric"
"The heating element is good (as I can feel the stack getting hot on either propane or electric)."

So yes, it seems pretty obvious.
Unless both heating element and propane system quit working properly at exactly the same time or the flue just suddenly is in need of cleaning. 😉

[SJ-Chris]

I have decided that most likely the cooling unit is bad.

I ordered a new Amish built cooling unit that will arrive in about a week. Since I'm going through all the hassle and have the fridge out and take apart, I will also replace the heating element (~$35) and the thermistor (~$25).

I'll let you know how it goes once I receive everything and get it all back together.

Thanks all for the help!
-Chris

[Old-Biscuit]

Boon Docker wrote:
I think it is pretty straight forward.
If the boiler is heating properly as the OP stated and no cooling, the cooling unit is shot.

Was it??

Electric Element being supplied full 120VAC Voltage
Electric Element transferring heat...holder not rusted inside
LP System Pressure at 11"WC
Orifice flowing correct amount of propane...no obstruction
Flame at full temperature
Flue/Flue baffle clean

Testing is only way to KNOW if cooling unit is good or bad
UNLESS obvious signs of leakage...ammonia smell/yellowish residue

[Boon_Docker]

I think it is pretty straight forward.
If the boiler is heating properly as the OP stated and no cooling, the cooling unit is shot.

[IAMICHABOD]

I am very interested in this thread,I see that you have a Former Rental and as of yet there has been no members of that thread that have had a failure of the refrigerator.

I will be looking for the outcome of this. I can only assume that you did not get the extended service contract.“extended warranty,” as they like to call it.

[Old-Biscuit]

dougrainer wrote:
You ALWAYS wire the 120 element DIRECT to 120 power to test a CU. Just 2 wires and connect to an extension cord. Run 24 hours. IF the FREEZER does not get cold or below 10 degrees the CU is bad. IF the lower section does not get below 38 degrees the CU is bad. Now, I am not a fan of rebuilt as a Service Shop. IF they are defective they do not pay a fair labor for the shop to diag and replace the defective unit. Now, IF or you are doing the work yourself, I would go with a Rebuilt. That way, IF it is bad, you have the time to replace the defective unit. BTW, Dometic and rebuilders BOTH have replacement CU's for your model. I would never trust that so called RV shop again. Doug

PS, I don't know where that poster got his info that a defective Thermister will freeze or get extremely cold. WIVES TALE. I have yet to see a Thermister make a BAD CU freeze or get extremely cold. Yes, they can cause too low temps, but don't use that as a guideline for Diag on a cooling problem.

If cooling unit is functioning a bad thermistor will cause overcooling due to limp mode/bos
Unplugging thermistor leads and running fridge can help determine if cooling unit is capable of cooling.
And if it is...then replace the thermistor

If NOT...then force cool by plugging element leads in directly to outlet and run fridge
IF it gets cold...bad circuit board
IF it does NOT...bad cooling unit

But kinda mute point now cause OP has already removed cooling unit so testing of cooling unit is futile.

[dougrainer]

You ALWAYS wire the 120 element DIRECT to 120 power to test a CU. Just 2 wires and connect to an extension cord. Run 24 hours. IF the FREEZER does not get cold or below 10 degrees the CU is bad. IF the lower section does not get below 38 degrees the CU is bad. Now, I am not a fan of rebuilt as a Service Shop. IF they are defective they do not pay a fair labor for the shop to diag and replace the defective unit. Now, IF or you are doing the work yourself, I would go with a Rebuilt. That way, IF it is bad, you have the time to replace the defective unit. BTW, Dometic and rebuilders BOTH have replacement CU's for your model. I would never trust that so called RV shop again. Doug

PS, I don't know where that poster got his info that a defective Thermister will freeze or get extremely cold. WIVES TALE. I have yet to see a Thermister make a BAD CU freeze or get extremely cold. Yes, they can cause too low temps, but don't use that as a guideline for Diag on a cooling problem.