How to stop the fridge from icing up - dehumidifier?

[MagicalArmchair]

Our Bavaria 40 has a fridge that works really well... for about a day, then the evaporator plates all freeze up and cold air stops circulating around the fridge .

I've added some seals to the top of the fridge to try and stop moisture getting in to help prevent it freezing up. Would a desiccant dehumidifier in the fridge help this?

The alternative is get a separate Dometic unit and just use the fridge as a cool box?

 

[B27]

Where is all the water coming from?
That's either a lot of airflow or you are freeze-drying your food?

 

[wonkywinch]

Check all your door seals, air is getting in.

 

[Hoolie]

Our fridge has an oval flat plate evaporator that gets cold enough for ice cubes but doesn't ice up enough to stop the fridge working. Maybe a flat plate evaporator would be better than the finned version you have?

 

[ashtead]

I guess not a new unit ? Does it have a control for temp which works ? Does running fridge warmer help? How good is air circ to fridge motor as maybe poor circ is causing issue ? Does this happen in any external temp or just in summer? Do you know of boat fridge engineer in your area as this might help?

 

[RunAgroundHard]

Often fridges start to freeze when the drain is blocked. Inside, usually at the back, sometimes in the base, sometimes on a dedicated recess a bit higher up with a run off gutter, there will be a hole. Outside the fridge this hole is usually attached to a tube that goes into the bilge or a cup. On domestic fridges it can drain onto a flat plate above the compressor where water just evaporates away.

The point is, the drain hole gets blocked which means the water freezes inside the fridge. Unblock the hole and any drain hose and your problem could go away.

 

[JOHNPEET]

The normal cycle for a fridge is that the compressor runs until the temperature drops within the cooled space to the set point 4/6 deg C. Then the thermostat stops the compressor and the air in the fridge being above freezing point, then allows any ice that has formed on the evaporator to thaw. So the questions are - is the set point of the thermostat being reached and switching the compressor off? Is the insulation enclosing the cooled space adequate and in good condition? Are the seals on the lid/door in good condition? There is also a possibility if the insulation and seals are in good condition that the refrigeration unit is unable to drop the temperature sufficiently due to a shortage of refrigerant caused by a tiny leak.

 

[JOHNPEET]

Also, to reduce icing - make sure that all food is wrapped or covered.

 

[MagicalArmchair]

Check all your door seals, air is getting in.

The standard Bavaria fit top loading fridge has no seals at all on my 2003 boat, which is a bit bonkers. I fitted some draft exclusion strips, however, as there is no way of clamping the lid down, I don't think these added seals get compressed enough, or are the right thing.

Our fridge has an oval flat plate evaporator that gets cold enough for ice cubes but doesn't ice up enough to stop the fridge working. Maybe a flat plate evaporator would be better than the finned version you have?

I spoke to the Dometic stand at the boat shows, and they were super helpful. He said your type of evaporator (with a plate) was more modern and much better, and I should just swap it out for one of those. This is probably the best fit, but in season I don't want to waste any sailing days.

I guess not a new unit ? Does it have a control for temp which works ? Does running fridge warmer help? How good is air circ to fridge motor as maybe poor circ is causing issue ? Does this happen in any external temp or just in summer? Do you know of boat fridge engineer in your area as this might help?

Nope, it is as old as the boat (20 years!). The thermometer and temp control was replaced by a fridge engineer on a cruise two years ago and the whole system was re gassed and checked. The air circulation is the real problem, as when the unit freezes up, the air from the tiny fan (scroll down) on the fridge cannot pass enough air over the fins, meaning the fridge warms up and spoils all our food. We only go on longer adventures in summer, so I guess we have only noticed when it is hotter.

Not a bad idea talking to a fridge tech!!

Often fridges start to freeze when the drain is blocked. Inside, usually at the back, sometimes in the base, sometimes on a dedicated recess a bit higher up with a run off gutter, there will be a hole. Outside the fridge this hole is usually attached to a tube that goes into the bilge or a cup. On domestic fridges it can drain onto a flat plate above the compressor where water just evaporates away.

The point is, the drain hole gets blocked which means the water freezes inside the fridge. Unblock the hole and any drain hose and your problem could go away.

There is no drain on the standard Bavaria fit fridge. We just mop it out every day or so.

The normal cycle for a fridge is that the compressor runs until the temperature drops within the cooled space to the set point 4/6 deg C. Then the thermostat stops the compressor and the air in the fridge being above freezing point, then allows any ice that has formed on the evaporator to thaw. So the questions are - is the set point of the thermostat being reached and switching the compressor off? Is the insulation enclosing the cooled space adequate and in good condition? Are the seals on the lid/door in good condition? There is also a possibility if the insulation and seals are in good condition that the refrigeration unit is unable to drop the temperature sufficiently due to a shortage of refrigerant caused by a tiny leak.

As you can see from the above, the evaporator itself gets cold, and the compressor does stop (presumably because the fridge thinks it's all cold enough), however, the fridge itself is all very warm indeed away from the lump of ice sitting in the corner.

Also, to reduce icing - make sure that all food is wrapped or covered.

We always leave fruit and veg, like apples and carrots, out in an open container, so this is a good idea to put lids on everything!

Thanks for all your help.

So:

• Put all contents of fridge into sealed containers for a start.
• Guess I should look at a better seal for the top? Any ideas what to use with no clamp?
• In the mid term I could replace the unit with an L type evaporator plate type unit, replacing the old Danfoss unit.
• Is there anything I could put on the fins to stop the water condensing on them??? RainX???
• I might try and talk to a fridge tech also.

 

[William_H]

I wonder if that fan is working OK? If it is would it be possible to fit another fan next to it to improve air flow over evaporator. ol'will