Wednesday, November 29, 2023


Ask the RV Shrink: Reader asks, “Are all absorption fridges inefficient?”

Dear RV Shrink:
We bought a new trailer and the refrigerator is not staying cold enough. We have had it in the shop where fans have been added, outside shades have been installed, and airflow inspected. Do all absorption refrigerators work inefficiently? They say we are in normal temperature ranges, but it fluctuates wildly and gets very warm if we are camping in hot weather. I hate to be a complainer, but this just doesn’t seem acceptable and I want it fixed properly before our warranty runs out. Should I scream louder or get used to it? —Getting the cold shoulder and hot fridge in Fresno

Dear Fresno:
I am not an RV refrigerator repairman but have pretended to be one many times over the years. They are much better engineered today than they were two decades ago. I used to take mine out and roll it like a snowball to get the juices running again. You shouldn’t have to do that anymore.

Since you have a new trailer with a warranty,  I would put the ball right back in the manufacturer’s court. In my opinion, your refrigerator should be designed and installed efficiently enough to keep the box at 34 to 43 degrees without having to add fans and shades. A mechanic will usually check for airflow blockage, ammonia leaks, thermostat failure or failing heat source.

Most RVs are designed with a roof vent. Air enters the refrigerator access door and flows up past the absorption fins and out the roof vent, much like a woodstove chimney.

They most likely added fans because this was not happening naturally. Again, in my opinion, an RV without a roof vent will give you poor venting, thus poor cooling.

Often people find that bugs have built nests in the roof vent and blocked the venting process. Or if you have an ammonia leak you slowly start to experience temperature drop.

I have seen floor plans that rob the refrigerator of airflow so they can squeeze in some other amenity. Too much refrigerator for too little space will not allow the absorption process to operate properly.

My guess is that you have an airflow problem. You can help relieve the situation by removing the access door completely and giving the unit as much airflow as possible, but I would not accept that as my final solution. I would be screaming warranty until I didn’t have to do anything or add anything to make it work properly, hold an acceptable temperature range, and keep my beer good and cold.

If you have to sweat possible food loss until the sun sets, that is not happy camping. If it is a design flaw by the manufacturer, you are doing them a favor by forcing the issue and making them redesign that space.

If you have a side vent it will be much less efficient: Wind can stop convection entirely, and units tend to fail more often with that design. Probably not something you gave any thought to when making a buying decision, but now dealing with constantly.

The best designed and insulated refrigerator spaces will move hot air out away from the RV, allowing the refrigerator to work at peak level and help cool the RV interior.

Hope this sheds some light on your problem. Don’t be shy when talking to the manufacturer. Remember, “It is the squeaky wheel that gets the grease.” —Keep Smilin’, Richard Mallery aka Dr. R.V. Shrink

Read more of the RV Shrink’s advice here.

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Snayte (@guest_87071)
3 years ago

My trailer has the fridge on the slide with a side vent and it works just fine. I can and have frozen stuff in the refrigerator section in 90 degree heat.

Scott R. Ellis (@guest_86786)
3 years ago

Having had one RV with the refer in a slide (and therefore no roof vent), that configuration became a deal-killer as we shopped for the next one. Never again.

TIM (@guest_86653)
3 years ago

The common issue is incorrect installation. Read the installation manual for your model and then inspect what was done by the RV manufacturer. The clearances and venting are probably wrong.

rvgrandma (@guest_86634)
3 years ago

When we had the cooling unit replaced it did not cool like our old one. I find I have to push the thermostat up as far as it will go to get it cold.

Will it get cold on gas? We had one years ago that preferred gas over electric, otherwise the gas cooled it better. When I turn them off to defrost I will use gas to get it cold since it seems to cool my current one faster than electric, then switch to auto.

MikeJ (@guest_86469)
3 years ago

Besides everything mentioned above, on side vent rigs, make sure there is a baffle installed at the top above the fins directing air flow out the top vent. I installed a heater duct pipe (cut in half lengthwise to form a “C”) wedged behind the fins directing air out the upper vent.

CONNIE L SMITH (@guest_86439)
3 years ago

We did four things. Installed 2 fans in the vent pipe. That sort of worked. Purchased a thermistor online. That really really helped. Then spent the money for a fan system from smart rv products. You can Youtube it for more information and it goes inside the refrigerator. It helped lots and kept me from defrosting the refrigerator as often. Who wouldn’t like that part? Last we purchased wireless thermometers. They came from Acu Rite. That way we didn’t have to keep opening the refrigerator and or freezer to see the temperature.

Ed K (@guest_86430)
3 years ago

More than likely the manufacture of the RV didn’t install it correctly. Norcold and Dometic have very specific clearance requirements for installation and a lot of RV manufacturers don’t follow them and then the new owners have problems. Use a camera and stick it in the back and verify the clearance between the back wall and the reefer cooling fins and then look in the manuals for the reefer and see if they are correct. Most installations require 1″ or less and the less is better. Make sure there are no excessive clearances on top and the sides of the box also.

Bill Fisher (@guest_86342)
3 years ago

We fought the absorption reefer problem constantly with our first two travel trailers and added multiple fans both inside and out. Our current Montana came with a residential fridge with ice maker and what a joy to not have to worry about it staying cold.

Lee Ensminger (@guest_86269)
3 years ago

This doesn’t really help “cold shoulder’s” problem, since his unit is new, but is addressed more to the shrink’s comment, “I used to take mine out and roll it like a snowball to get the juices running again.” We own a 2004 motorhome with a side-by-side Dometic refrigerator/freezer. It’s running strong in 2020, in my opinion, because it is never turned off, except long enough to defrost it. We replaced the control board about three years ago, but it has never been a problem otherwise in 16 years. My strategy, and my personal opinion, is that many absorption refrigerator problems come from letting them sit unused for long periods of time.

Dr4Film (@guest_86358)
3 years ago
Reply to  Lee Ensminger

Or in the case of the Norcold 1200 series fridges which are fire hazards because they were poorly designed, having one of those in a coach is a disaster waiting to happen.

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