Community Forums

41magnum · 07-24-2020, 06:41 PM

we've been living bout full time in our 5th wheel for a few months
its been horribly hot and humid for a month.....90* and 90% humidity.

the Dometic fridge is getting iced up fins.......nearly 1/2 the fins are slightly icey now.

do we do an old timey defrost with jugs of hot water inside or what?

ALSO, is there a way to prevent this?

it typically keeps at 36-38* according to the thermometer i keep in there.

thanx folks

Jim_HiTek · 07-24-2020, 07:14 PM

Wow. 90F and 90%, that's a tough combination.

I'm nowhere near a humidity that high, but I've had 105F temps at 38% before for a couple weeks at a time earlier this year. And I've not had ANY frost on the fins at all. Over the last 4 years. Still get some in the freezer compartment but it's a year between cleanouts. But that's due to a DIY project that I accomplished back in '16 when I bought this rig. Adding a fan to the inside of the refer.

Here's the link to my ad free article about it. If your refer isn't a Norcold, you can find another article about the same process for a Dometic refer at my blog in the '94 Bounder section.

Refer fan installation...

Oh, I should mention...TEST your seal by putting a dollar bill in there and close the door. It should be difficult to pull it out. Also, you can look around the door seal for moisture. That will indicate a bad seal too. If you have a bad seal, it's costly as the refer manufacturers want you to replace the entire door.

Jon_C · 07-24-2020, 07:43 PM

It’s probably freezing up due to lack of air circulation.

leaving a little space at back of each rack helps the cold air work its way down to the lower levels.

And the fan mentioned will also help.

Ray,IN · 07-24-2020, 08:28 PM

Keep the doors closed as much as possible, really. Decide what you want before opening a door, yes I know, kids(large and small) like to window shop. Education is the key for that. Every time a door is opened the cold air spills out onto the floor only to be replaced with warmer humid air.

The absorbtion refrigerators do not have a defrost cycle, so yes warm water in jugs or a hair dryer work. On entended trips I do a defrost about once every 3-4 months.

Another thing that can cause frost buildup is the condensation drain tube. It must have the small plastic button in the end. It's purpose is to keep insects out plus reduce warm air flow back into the fridge. Norcolds have an evaporation cup near the heating elements that keep the tube end submerged in water. That prevents anything from getting into the fridge.
Dometic has the tube hanging outside the lower vent panel, so the plastic button is very important.

Fast E · 07-25-2020, 07:50 AM

All the above but double check door seals.

TXiceman · 07-25-2020, 09:12 AM

Circulation fan inside and check the door seals. It is normal to have some fin icing and you do need to defrost the unit periodically.

Ken

Neckl · 07-25-2020, 05:17 PM

I have an atwood refrigerator that ices up the fins when I run it on electric but not when I run it on gas. Weird or what? It is an HE0601 model 2006 build date.

keymastr · 07-25-2020, 09:31 PM

If it is just slightly iced as you say, it is doing pretty good, leave it alone. It seems to be doing a great job as is according to your thermometer. If that changes or the ice gets a lot thicker then you may need to defrost it but with those conditions it sounds like it is running well.

Teamfoxy · 07-26-2020, 06:33 AM

We had an icing issue last year, but changing the thermistor location slightly and making sure that we do not over pack the fridge has fixed it. No icing at all this year.

Xmcdog · 07-26-2020, 06:42 AM

Pretty normal in high humidity conditions. Should clear itself when temps and humidity drops.
Right now it is working very hard and the fins are very cold. Every time you open the door there is an inrush of warm, humid air that heads to the fins. Weak door seals make the condition worse.

Gary RVRoamer · 07-27-2020, 11:03 AM

Quote:

I have an atwood refrigerator that ices up the fins when I run it on electric but not when I run it on gas. Weird or what?

Not really weird. The fin has to get to 32 F. for ice to form, so it appears your fridge cooling unit is performing better (getting colder) on electric than on gas. It could be as little a 0.1 degree difference. If the electric mode heats the boiler a bit more than the gas burner, there can be a small difference in fin temperature.

baraff · 07-27-2020, 06:27 PM

I bought one of these. Even has blue LED lights (no idea why but it's cool). Works great, circulates the air in the fridge and keeps the fin pretty clear. I wired it into the fridge 12v circuit.

chunker · 07-28-2020, 05:18 AM

Quote:

Originally Posted by baraff

I bought one of these. Even has blue LED lights (no idea why but it's cool). Works great, circulates the air in the fridge and keeps the fin pretty clear. I wired it into the fridge 12v circuit.

You might check but I thought the thermistor was placed on the second fin about halfway down as a proper cooling position.

Isaac-1 · 07-28-2020, 06:02 AM

Another vote for a small circulation fan, I added one about 3 years ago and it really helped on ice buildup, I still need to defrost it with a hair dryer, but not nearly as often, maybe once per year now, even then it is not as bad.