Refer Operation – Generic info
If you read a lot of RV complaints on RV forums, one of the most oft repeated is the slow cool down phase of the refer, followed by complaints of the refer not getting cool enough. The freezer is usually OK, these complaints go, but the refer seems to get down to the mid 40’s and hover there.
Many of these complaints are justified, some are based on ignorance. I’ll give my thoughts on using the refer, keeping your refer healthy for years, and then let’s look at some of those other complaints one at a time. Keep in mind that an absorption refer is over one hundred years old so the design is sound. There have been reports of that style refer over 70 years old still operating in cabins in the woods. Their efficiency is legendary.
1) Lifetime: After reading hundreds of forum postings from people who had their RV refers fail, and from experts in the field, I developed my own theory about why those refers would last around 7 years before a catastrophic failure like an ammonia smell inside the refer, or yellow reside on the coils in back, and that was moisture. What was happening was that people would pull out their RV early in spring, dust it off, clean it up and fire up the refer to be ready for a summer of travel. Between trips, the refer would be emptied and shut off as the RV sat without power next to the owners house. At the end of the season, it would go back into storage, again, without power generally. Most of the stories I read where there had been a refer failure came at around 7 years old. [As it turned out, the 10 year old RV I bought back in 2004 had a bad refer so I spent hours researching. I knew about it not working, so when I was negotiating price, that played a large part in reducing what I paid. When I bought it, the refer was 10 years old, and had been sitting on the lot for nearly two years.]
Turning the refer off will allow moisture to condense on the outside coils. If this moisture doesn’t evaporate quickly enough, small pinholes of rust will develop on the surface of the tubing, and over time, grow. Eventually, a pinhole will develop and allow the chemicals inside the tubing to escape. (Yellow residue on the coil indicates a leak.) This rusting process is exacerbated by: salty air, moisture laden air, large temperature differential between the heated coils and the air at turn off, and turning off the refer too often. To prevent or at least reduce the odds of early absorption refer failure, try to follow these suggestions:
A) After a trip, especially after a trip to the ocean, or a trip on salted roads, turn off the propane and all power, shore and battery. Than cover the circuitry and area where the propane nozzle is with a plastic mat while you gently spray off the coils with clean water. This removes salts. Than turn on the refer as soon as you can. This is to heat up the coils so moisture will evaporate. Do this on a relatively dry day if you intend to turn off the refer later.
B) Never turn the refer off (except for short periods, like when defrosting, or cleaning). This means plugging your RV into a 15-20 AMP outlet when at home or renting a powered storage space. The refer draws very little when on AC so a 15-20 AMP circuit is fine.
C) One common failure mode is noticeable because of a strong ammonia smell in the freezer. I believe this can be caused by overloading the freezer shelf (which acts as the evaporator) in the Dometic style refers. The Norcolds don’t use this type of design. Repeatedly cramming frozen food between the ceiling of the freezer and this shelf flexes the relatively weak tubing that supports it, causing fatigue cracks. Which leads to leaks. Than as you drive, the jarring of the shelf with heavy frozen food on top of it causes even more stress on the tubing. Nothing to do about this other than to avoid overloading that shelf. And never stuff it so full that that foods contact the ceiling of the freezer.
2) Slow cool down: This one is typical of all absorption refers…a longer cool down period when first turned on as compared to modern kitchen refers. This is the nature of the beast and fully normal for absorption refers. It’s a complete chemical process and takes time to get going. But you can speed up and help the process along, and here are several things to take into account when turning on the refer after a down time:
A) Make sure the refer is as level as possible before turning it on. This is particularly important for refers made before the mid ’90’s. If possible, pull out the awning to shade the portion of RV where the refer is housed, or move the RV to a shady spot. If you’re going to run it on propane and battery at first, make sure you check the gas nozzle and clean out the area of debris or cobwebs before turn on. There’s one species of spider in the south that really loves the smell of propane and builds their web right on top of the nozzle. Note that most RVs can generally battery power the refer for 3 days (with newer batteries) but it wouldn’t hurt to start and run the engine at 1300 RPM once per day to keep them charged up. Or, just plug into a 120V 15A source. Since only a few items would be on the circuit, a 15 Amp supply is fine. Just don’t try to run the A/C.
B) Turn on the refer at least 24 hours prior to travel. If ambient temps are high, turn on a day earlier then you would if daily temps are more moderate. In any case, turn it on at least 24 hours before departure.
C) The day before departure, and/or shortly after you’ve turned on the refer, fill the freezer with frozen items (except ice cream or similar) and fill the refer section with frozen and cold items. Leave perishables, and ice cream, in the home refer until just before you leave home. Putting cold items in the refer and freezer sections helps to rapidly lower the temps inside the refer, which helps the mechanism reach proper temps faster. Cooled canned drinks, juices, and the like are preferred over perishables to start with. As it gets cooler, it’s OK to add perishables.
D) Place frozen plastic bottles of water or juice inside the refer and freezer to speed up the process. Remember heat rises and cold falls so try to put frozen items up high in each compartment if possible. I use unopened 64 oz fruit juice bottles or empties I’ve filled with water and frozen. Than after it’s gotten cold enough in the refer, store the extra juice in the pantry to free up room in the refer. Using juice that I end up taking with me is so I won’t have to buy more on the road at exorbitant prices. (I tend to watch the juice bottles closely in the home freezer and when the bottle starts to deform, I move them out to the RV. Don’t want them to burst. Sometimes this makes a mix of frozen and liquid inside the bottle. No matter, it’ll work).
E) Add a commercially available fan. These are battery operated and are placed in the bottom of the refer. They help stir the air around which promotes rapid cooling as well as help maintain even cooling throughout the refer. OR, follow the DIY suggestions here.
3) Not getting cool enough – on the road: If you’ve followed my advice in section 2) above, if should be cool in the refer and cold in the freezer. You’re ready to go, head out, and the first night you park, the refer doesn’t seem cool enough though the freezer is fine.
A) Road wind can and does blow out the refer’s gas flame while you are driving, especially a quartering wind hitting the outside refer plate at just the right angle. It doesn’t hurt to have your burn assembly cleaned and adjusted before travel (plenty of online examples and guides on how to do that yourself). Modern refers automatically restart the flame but then the wind hits it again, flame goes out, it’s restarted, and so on. There’s a delay between each restart. This causes the refer to slowly warm.
B) Overfilling. Plan on having less in your refer than you think you need and just buy more often. Too much warm food stuffed in there warms it up and decreases air flowing around the foods. If you’re driving every day, for just a couple three days, it’s probably not going to matter if the refer warms up a few degrees while you’re driving. If it’s going to be a longer drive time than that, just buy fewer perishables and try not to overfill the refer.
C) I try to manage what I buy on the road more than I would at home…for instance, I always buy Ultra Pasteurized milk on the road. Or when I can’t find it, almond or soy milk. I also avoid items that tend to spoil too fast, like strawberries or fruits that bruise too easily like thin skinned pears. When I buy meats, it’s specifically for freezing. Only have one or two night’s meals in the refer at a time. If I forget to take out something to defrost the night before, I’ll put it in a bowl inside the stainless sink while I’m driving. Or I might use the MW to defrost. Or it’ll give me an excuse to eat out. Heh.
4) Not staying cool enough – at the campground: This could point to a serious issue, but I’ll cover some simple and not-so-serious reasons why this could happen, especially if you camp in the summer. These hints are if the refer is mostly level, it’s been serviced and pronounced good, and the freezer portion is nice and cold but the refer tends to be a little warmer then you like.
A) Adjust the plastic temp controller inside the refer (generally on the last fin of the cooling assembly nearest the light). Slide it up on the fin to decrease temp. Also, on the refer eyebrow and/or controller, set the temp for cooler. And of course, limit the number of door openings and closings. Plan your refer visits. Keep in mind the long lag between changing a setting and seeing results.
B) Try to park in the shade or use your awning so the entire refer, including the outside cabinet, is shaded and doesn’t have to work too hard.
C) As when you are traveling, try not to overfill.
D) If you’re a daily shopper, shop nearby, that is, don’t drive 30 miles away to save a few bucks on a hot day. Shopping nearby means your items will tend to have maintained a lower temp by the time you stick them in the refer.
E) Freeze a bottle of water in the freezer overnight and plop it on the top shelf of the refer in the morning. You’d probably only need to do this on really hot days when you have no shade and the side of the RV with the refer gets the afternoon sun. And/or if your A/C isn’t working.
F) Defrost! This can’t be stressed enough. If you’re in, say, Florida, you’ll quickly find frost both on the fins in the back inside of the refer, but up in the freezer too. And it soon morphs into ice. Keeping that frost down is very important because the refer has to work hard to keep it frozen. There are absorption refers with an automatic defrost cycle but if you don’t have one, the best way YOU can automatically defrost is by installing an inside refer fan, and I’ll show you how I made a DIY version here. You can also buy one from Amazon or others, but I’d wager it doesn’t work near as well as mine. I hear adding a chimney fan helps too, though I haven’t added one to test that theory.
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