Absorption fridge rebuild not so good.

[oediehl]

My circa 2007 Norcold 1200 was not cooling so well, and I waffled between a residential replacement and an Amish-built cooling unit replacement. Decided on the latter, and $1500+ and many hours labor later, it was done. Also replaced the fans and added a relay and cooling fan baffle plate (RV Cooling Unit Warehouse), and the ARP device designed to prevent overheating. Also a new LP regulator for the RV. From the start seemed to alternate between cooling so well that I needed to set the temp down around 3 to keep the fridge from freezing, and other times not working so well, but after fiddling a while it seemed to have settled in to a good strong pattern, even on days with the outdoor temps in the 80s.

 

So off we went on our 2-3 month tour. The first week it worked fine, but yesterday, while transferring from Oklahoma City to Amarillo, the temps in the fridge rose to the 60s. I piled stuff in the freezer and hoped that maybe the furnace flame had blown out in transit because of the strong side winds, and this morning it had cooled back down to almost acceptable temps. But with the temp set at max, today, with outdoor temps in the 90s, the freezer came back above freezing (it had previously been staying well below 0), and the fridge also warmed up. I didn't open the doors to the refrigerator at all between 9 AM and 5 PM.

 

I'm at a loss as to why I seeing such variability, Early on I talked to Dave at RV Cooling Unit Warehouse, and based on his comments I pulled the fridge back out and used another partial can of the spray foam sealant, to plug any gaps I might have left where the cool air could leak out. I also used a temperature sensor gun to look for leaks around the door seals.

 

The ARP is reporting consistent boiler temps around 170 or so, and the coil temperature around 130 degrees.The exterior fans stay on pretty much all the time, as best I can tell. Earlier, when outdoor temps were cool and all was working well, the exterior fans would often not be running.

 

Dang! Guess I'll have to not depend too much on the fridge for this trip, and think about a residential Samsung after we're back home.

[TXiceman]

When replacing the cooling unit, you have to have a absolutely perfect seal around the unit. It is hard to get the unit back together with a perfect seal. Sounds like you have a moisture leak. You will need to pull the unit apart and dry it out and try to get a better seal when you reassemble.

 

Ken

[Kirk W]

I have not had the experience of replacing a cooling unit, but the wide swing of temperatures sounds like a control problem, particularly when added to temperature history on the boiler area. That indicates that it isn't overheating as it would if refrigerant were not flowing. What we don't know is whether the system has been operating constantly, as it would seem to have when it got too cold, or may it be failing to call for cooling as it should when interior temperatures rise.

[Randyretired]

On our refrigerator we added a 3rd fan along with the other items you noted when we changed the cooling unit. It has worked well for us in temperatures up to 100F. We avoid temperatures above that. I plan to add yet another fan to be sure the unit is as effecient as possible. These fans are thermostatically controlled so over cooling isn't a concern. The fans are cheap and use very little power.