Author Topic: Fix or replace fridge compressor?  (Read 3254 times)

Krumelur

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Fix or replace fridge compressor?
« on: October 05 2021, 14:04 »
My Bav 40 has a top loader fridge with a WAECO cooling element.
The compressor in the cabinet below is still the original from 2010.
The fridge's temperature is well above my expectations and I'd like to fix it.

Wondering what my options are.

Compressor:
Is it possible to refill the compressor? Or should I better invest into a new one? If new: any recommendations?

Cooling element:
Do I have change the cooling element, too, when replacing the compressor? Or is that element maybe the more important part to change?

newtom

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Re: Fix or replace fridge compressor?
« Reply #1 on: October 05 2021, 14:14 »
Hi,
I changed my 20 years old fridge 1:1 with a dometic CU94 and a VD15.
1 h remove, 2 hs Installation of the new parts. Carefully connect the 2 parts!

Regards Tom

Krumelur

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Re: Fix or replace fridge compressor?
« Reply #2 on: October 05 2021, 15:30 »
Sounds good. And it's just another small investment of 1 grand.
Seems to be the base unit for all work on a boat!  ;D

SYJetzt

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Re: Fix or replace fridge compressor?
« Reply #3 on: October 05 2021, 15:41 »
Changing the cooling element and the compressor will not solve the main problem of the bad insulation of the box and the stupid construction..
The box will be heated up by the aircooled condensor and the compressor mounted beneath.
Checking for leaks and refilling the refrigerant is cheap (if nessecary).
I improved the base insulation on the top side of the compressor locker first and added a blower to get cold air in and another blower to get warm air out.
This reduced the running time of the compressor and saved a lot of energy drawn from the batteries.


SYJetzt

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Re: Fix or replace fridge compressor?
« Reply #4 on: October 05 2021, 15:47 »
If you are thinking about ripping the stuff out, i would suggest a water cooled condensor (like the isotherm SP-systems have). With this mod you bring away the warm air beneath the box, and do not heat up your saloon with the fridge. This applies especially for cruisers in warmer climate (like the med!).

Keweetoo

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Re: Fix or replace fridge compressor?
« Reply #5 on: October 05 2021, 19:20 »
Before ripping out the old compressor check to see if its just a case of needing a gas top up which most marina engineers can do relatively cheaply. Typical fault is the compressor is working hard (doesn't switch off as the fridge not getting to set temperature) and the evaporator plate may be iced up on a section  but not cold overall. Whatever you do its well worth improving the insulation around the fridge with expanding foam or insulation.

Odysseus

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Re: Fix or replace fridge compressor?
« Reply #6 on: October 06 2021, 09:12 »
Reply to the water cooled compressor that should be taken into account when live aboard.

1 it does not work when lifted out.

2 it continually gets  logged up with crustations

Another hole in the  boat.

Odysseus.
Odysseus

kavok

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Re: Fix or replace fridge compressor?
« Reply #7 on: October 06 2021, 10:11 »
https://forum.amicidellavela.it/showthread.php?tid=133865

Here all my fridge jobs. Now works well, only 20 minuts per hour in 30 Celsius air degrees. Thermostat between 4 and 8 degrees. 4,7 amp when running.

mutluthesailor

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Re: Fix or replace fridge compressor?
« Reply #8 on: October 21 2021, 12:40 »
Changing the cooling element and the compressor will not solve the main problem of the bad insulation of the box and the stupid construction..
The box will be heated up by the aircooled condensor and the compressor mounted beneath.
Checking for leaks and refilling the refrigerant is cheap (if nessecary).
I improved the base insulation on the top side of the compressor locker first and added a blower to get cold air in and another blower to get warm air out.
This reduced the running time of the compressor and saved a lot of energy drawn from the batteries.

actually this was the main problem i also had my Bav 40 2011. Bottom of the fridge box was heated bcs of the hot air from the condensor so there was always some water down below the cool box. Solution is simple and not expensive.

Trundletruc

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Re: Fix or replace fridge compressor?
« Reply #9 on: October 22 2021, 19:23 »
I changed the original Waeco fridge for a water cooled one with an additional fan. The heat exchanger in the water works great and when afloat the already warm cabin (we are in Greece) does not get further heating from the fan! When we are in the boat yard we switch on the fan and the fridge works better than the old one did. With no fan it is far quieter when afloat too. The unit is a Frigoboat and Penguin Refrigeration were very helpful. 02392453430 giving me advice on how to put it in.
The water cooler has 2 anodes which need replacing occasionally and a scrape soon gets the nasties off. Our water cooler can just be reached when afloat and I am swimming. Expensive but much much better than the original fridge, worth every penny.
We always put a mat on the top of the lid at nights to help conserve the cold inside.

SorinCT

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Re: Fix or replace fridge compressor?
« Reply #10 on: October 23 2021, 09:18 »
For my 36c the weakest point is the fridge insulation. So far i have cleaned condenser, evaporator, fans, replaced thermostat twice and fiddled with the settings of the compressor.
I went through the process of making a pressure test initially then refill the system with fresh freon. My evaporator fan is wired to be permanently on. In my opinion the the tradeoff is worth while to keep the system working correctly.

My initial capillary tube thermostat was jammed in the evaporator plate, basically sensing the surface temperature of the evaporator. Short cycling was an issue and i have currently replaced it with a 12v electronic thermostat with adjustable hysteresis with the sensing probe located near the shelf in the fridge. Since tuning of parameters i am now getting 15-20 min run time and 1h off, 8 degrees setpoint, 3 degrees hysteresis and ambient 15-20.

Top lid had no gasket and i kind of improvised one although not completely happy about the fit. The worst part is the open cell foam insulation around the fridge box which i am sure is soaking up humidity (dew point). There is no easy way of removing the box and re-insulating it and most likely it will require re-tubing of gas lines and loss of freon. If i were to do redo everything i would install quick connectors on both sides and use normal evaporator plate, not the flimsy aluminum finned one. It makes cleaning very easy and less chance of mold growth.
Few years ago designed a custom made fridge for my old boat, out of Okume plywood and foam core panels (like for PVC windows). Did my math and ended up with a good balance between internal volume and efficiency and it worked great with minimum power consumption (4 A, 12 minutes every 1 hour). It did help that the lid had double gaskets and latched closed keeping a good seal.

As for the compressor and electronic unit, mine are located under the saloon bench seat and do not warm up the fridge compartment. They are very reliable and have lots of features like over/under voltage protection (compressor trips if you drop below a set voltage), motor speed adjustment (better efficiency in some applications). The diagnostic pin can also be wired and can tell you by a series of flashes if you have any issues with the system.