Freezer problem

[Cam Whitlock]

The freezer on my Oceanis 40 runs great, but never cycles off.  The thermostat is a Vitrofrigo, just replaced it.  The compressor is a Danfoss BD35F.  Any suggestions / solutions?

[Randy Brown]

It could possibly be something stuck in the "open" position.  Thermostatic expansion valve?

It's been a while since I had that class in marine engineering.  You can google this, It not too different from an A/C system.

Good luck.

[Cam Whitlock]

Thanks for the suggestion, I’ll check that out.

[Mike Brown]

We experienced the same thing on our B43 (now sold and gone). We were living aboard and cruising with a fairly full freezer. Like you did I changed out the thermostat without success. I wrote it off to the poorly insulated freezer compartment but always wondered if there wasn't a bigger issue. The good news is that the Danfoss compressors are quite happy to run constantly with no reliability issues. 

Good luck and enjoy the boat.

Mike

[Cam Whitlock]

Hey Mike - I agree with you that there is no physical problem with the unit running.  My problem is the drain on the battery.  As a weekend / once / twice a year cruiser, I don’t have solar to recharge my batteries (yet).  I have my doubts that it’s the insulation as it freezes the items in the freezer easily and can frost them up if let to run for days at a time.  My current thinking is that I think it’s something mechanical or the controller.  Last weekend I found the evaporator for both the freezer and fridge are both heavily crusted with dust from 10 years of use.  To clean this the challenge is trying to determine how to get to the coil to clean it. The wood louvers in the cabinetry don’t appear to be removable like the A/C returns.  The only other option I currently see is to remove the evaporator which may mean removing the entire condensing assembly.  

Cheers,

Cam

[Mike Brown]

Cam, keeping the coils clean is essential to max efficiency for both units. For whatever reason our 43 required constant upkeep to keep the coils clean. The wood grates are glued on but can be removed if you work at it using a tool that won't mark the wood. I started at a corner and gently pried a little at a time working my way around and back and forth until they came off. I was able to push them back in place and have them stay put. Once the grills are off you can use a small painters brush to clean the coils. A vacuum cleaner helps. As do pipe cleaners and a flashlight. I'd turn both units off until they're clean to prevent any tool you're using from jamming up the cooling fan blades. 

I also installed two stainless vents, one above each compressor, to allow the heat to escape. There's an opening at the back of the box they sit in but I found it was better to vent directly above each unit.

Another thing you can do is buy a small wire rack to sit in the bottom of the freezer. I bought one with a painted finish, then cut the legs so the rack sat apx 1" off the bottom. This will allow for some air flow which will help keep items frozen all the way around. 

While you're working on the units inspect the connectors for the 12V feed to the compressors. They have a voltage drop across them and tend to heat up which breaks down the connection, causing more heat, more voltage drop and so on.

Lots of little things add up to greater efficiency.

I hope this helps.

Mike

[Cam Whitlock]

Mike - great information!  I was hoping that there is a way to remove the wood grills. What type of tool did you find worked that didn’t damage the wood?  

[Mike Brown]

Cam, I used a wide, flat blade screw driver to pry it off. I took my time and made sure I wasn't forcing it and causing any dents or scratches. It took a little while to do but when done I had good access to the coils. One of the grills would push back into place and stay put. The other would not stay put so I folded a small piece of paper (1/2" square) and folded it to create a wedge. Simply set it on the recessed edge and push the grill into place. The paper should hold it there until you pull it off for cleaning.

Take your time and be careful not to force anything.

Good luck

Mike

[Cam Whitlock]

Thanks for the details, this really helps. It will be a few weeks before I get a chance to tackle this. 

Fair winds!

Cam

[sam]

Mike nails the freezer (and Refrigerator) item. Remove the woodencovers on the vents, and if they have never been off you will most likely find a carpet of dust/hair/lint. I drilled small screw holes and added screws to re-attach. Now it is a bi-monthly service item. I use a dental instrument that has a soft brush about an eighth of an inch in diameter. The head brushes are disposable.

I also added much insulation to the freezer, having removed the oven/stove and drilling holes to gain access  the outboard side. Also pulled the refrigerator out and added a damn under the bottom of the freezer and then filled that area with foam also. I have the two cabin with the aft galley.

Sam

s/v LONGHAWK b43, Hull#9

[Cam Whitlock]

Sam - thanks for the additional detail on the insulation. 

[Brendan Smyth]

Seems there are two issue:

1.  Poorly insulated (for sure behind the refrigerator)

2.  Periodic coil cleaning, is required.

I have am considering spray-in insulation - any recommendations are welcome?

How did you remove the wood panels to gain access to the coils?