Replacement Fridge in 23d (CB)

[CruizinDux]

I wanted to follow up on my posts 14 & 17 . I had installed a small fan midway horizontally that I had laying around but in the end it sounded like a freight train. I bought (about $20 at WM) a SilenX that is rated at 15 DB and 42 CFM. Basically it's silent. I slipped a few small pieces of my old back backing ensolite pad between it and the alu panel to lesson any vibrations.


I also used two T-Nuts from the back of the panel with a couple of 1/8 x 4" bolts so I can easily remove the fan if needed at a later date.




Seems it was this thread that someone mentioned a reset button for the refer ele heating element. Kinda stumbled on to it by accident as you need some good light to see it. See image.


also removed the upper rubber edging so it exposed the fins a bit more

[CruizinDux]

Originally Posted by pcskier

Well, my rebuilt cooling unit arrived yesterday. Meanwhile, I had turned off my fridge (which was doing ‘ok’—-20 degrees in freezer and 40 or so in fridge) to give it a good cleaning since it’s pretty much empty. Turned it back on, and within hours the freezer was 2 degrees and the fridge at 34. Perfect operation, on the day my cooling unit arrived lol.

But I do know mine has crystals in the solution that will rear their head again, so I’ll proceed with the project~~but I now have an excuse to delay it until I feel like it—or the fridge quits again ��. They allow up to a year to return the old core to get back the $100 core charge.

Peter did you ever post a thread re the install of your Amish rebuilt unit from rvcoolingunit.com (David)? Any feedback?

[CruizinDux]

Just an aside, we got a couple days midweek in at Meramec SP this week and had a chance to checkout the new 3rd fan. It helped but only a little.



After 6 hours it was only 31 in the freezer and 50 in the refer compartment but had only been on for 8 hours and it was in the mid 80's.


The next morning better but still not there thinking 20 & low 40's. That afternoon around 5 pm I added some cardboard baffling (very rube goldberg, but wanted something to test the method first) that I had mocked up and it started to drop slowly. By 9 am the next morning it was 0 & 33. Well OK. All three fans running but the upper two turned off sometime after midnight.



With a hand gun I took some reading on the tubes and certainly just below the two elbow above the burner was the hot spot at 120give or take. I took reading at he various elbows and working my way down 102 at the top on left, the next 180 was 82-90...dropped down to 84 >>then up to 89, 92, 97 at the lowest series. So to recap, 1st corner above the burner, very hot...works it's way left over the condenser fins and turns down...102. Next course was 84...the each successive course was higher than than the previous.


Not sure what this means but suspect I have some minor blockage at the first elbow and maybe a little less so at the bottom of the tubes.


Certainly with the mock up it is workable. When we emptied the refer to the ice box (as it was a quick drop and go at storage), it jumped to 3 & 41 or so, but had dropped back down to 0 & 37 ?? by the time we reached storage. Certainly workable. But long term, thinking amish rebuild is the path. (either at David/rvcoolinguint.com or National RV Refrigeration Shipshewana, IN )


BTW will replace the Rube cardboard for some clear plastic for now. I had a thermo that I wanted to be able to see on the back of the refer to monitor outside temps in the upper compartment near the top of the burner tube. Also the two remote sensors and the display worked great. Easy to keep an eye on temps without having to open the door.

[pcskier]

My cooling unit is still in the box. My fridge became pretty reliable so I havent gotten around to the swap yet. I was housesitting for a couple weeks and had the fridge turned off. When I turned it back on (electric) the freezer was 5 degrees within a couple hours (starting from about 55). It wanders around from zero to 20-25 degrees, with the fridge in the 30s.

Doing the swap is planned for next month or two now that the weather is nice and I’m on my property in the AS for the summer. I’ll check in when I get it done.

[Boxite]

The installation instructions for Dometic reefers is available online
https://www.dometic.com/assets/86/36..._rev_48636.pdf

and most of just leap to the conclusion we need more cooling-fan to get this thing to get cold….

…but the problem I’ve seen is that heating coil/flame flue exits hot air …right BESIDE the condenser fins…. keeping them HOT. Those cooling fins stay hot if you circulate hot air over those fins with addt’l fans…

But what makes a big difference is getting the heater-exhaust to actually EXHAUST somewhere other than nearby the condenser fins. The installation instructions Dometic publishes are usually disregarded by Airstream Installers.
I’ve never seen the “Gas Flue 3776” on an Airstream which is intended to Exhaust the hot gases from the heating unit AWAY from the condenser fins.

If I’m seeing the photo correctly…. it looks to me like CruizinDux last pic…. shows the fans sucking all the ventilation compartment air right-thru those condenser fins…. including the hot exhaust gases from the heater unit.

[CruizinDux]

Boxite, interesting indeed. I’ve read the Dometic OEM install manual many times and have not seen a reference to this part. As part of my recent refer fiasco on a trip to CA last year, I requested and rec a newer “oem” install. While it addresses insulation requirements and shows the lower horizontal fan as an option, there is no reference to this vent part that I remember. I’ll look at your link on a larger screen and reread both install manuals…again.

This part appears to be applicable to rm4601 which is a much larger refer system, but still worthy of investigation…I like the concept. While my fans primarily pull the, in theory, cooler air up from the bottom, thru the lower tubes, then out over the condensing fins, dealing with the much hotter burn tube air, gets pulled from the side and out with the rest. Maybe a vertical separation baffle??
I can’t disagree with you, but have never see this mentioned or spec’s on any AF threads.

Thanks for the info…I think Certainly an option to think about.
Happy trails

[CruizinDux]

Peter I saw this service manual reference in another thread for a 2516


https://www.airforums.com/forums/f42...ml#post2606997


but googled it for my 2451. Your 2551 is also covered.


This is a pretty good service manual