Repair a Liebherr Refrigerator With Wine Cooler Compartment SBSes7165 (SWTNes3010 and SKBes4213)

This instructable is written for the repair of a Liebherr side-by-side SBSes 7165 but it will be applicable to most of other Liebherr freezers, especially those with wine compartments.

The SBSes 7165 consists of a Liebherr SWTNes 3010 (with wine compartments in the top and a freezer in the bottom) (this device had to be repaired) and a Liebherr SKBes 4213 (a refrigerator, which is still ok).

Our device was 11 years old (in june 2022) and it was in a good condition.

After repair it works until today (june 2023) without any problems.

You will need basic refrigeration technology like a vacuum pump, a manifold, special hoses and the cooling gas (in this case R600a). We were completely inexperienced with refrigeration technology beforehand and had to buy the manifold, hoses and installation stuff.

In the middle of the night, you may hear an annoying alarm sound from your loved Liebherr device. You may then reset the alarm and have the same procedure in the next night and in the next night and in ...

To escape this sequence, go to your Liebherr service menu: 

• Push power button und arrow-up button (at the right side of the display) for 7 seconds simultaneously (video).
• Select menus with arrow-up and arrow-down. Confirm with ** (Superfrost) button and again ** to see individual values. Go back with the power button.
• The menu entries are explained differently in service manuals for various Liebherr devices. Here is what worked for us:

Menus

• L (Loads) with submenus L', ...
• L'
• 0 - all off?
• 1 - compressor on and valves for upper wine compartment
• 2 - compressor on and valves for lower wine compartment
• 3 - fan for freezer
• 4 - ?
• 5 - lights in wine compartments
• 6 - heating for upper wine compartment
• 7 - fan upper wine compartment 
• 8 - fast fan upper wine compartment 
• 9 - heating for lower wine compartment
• A - fan lower wine compartment 
• B - fast fan lower wine compartment 
• C - compressor on and valves for freezer
• E (Sensors) - with submenus E', ...
• E'
• 3 - sensor freezer (air)
• 4 - sensor freezer (evaporator)
• 8 - sensor upper wine compartment 
• 7 - ambient sensor? 
• 1 - sensor lower wine compartment   
• 7 - ambient sensor?
• A - door wine compartments 
• B - door freezer

Have a look at sensors 3 and 4 

• If sensor values are not plausible, you may have defective sensors. They are easy to get and to replace. You will find instructions on the web.
• If sensor 4 is very cold (<-20°C) and sensor 3 is not, you will have a defrosting problem, wich is typical for these Liebherr devices. A solution is described in the next step.
• If both sensors are too warm (>-15°C), you will have a cooling problem. Possible solutions are described from step 4 on.

We had problems with the automatic defrosting system twice in the last 5 years.

This is what happens: Dirt remains in the drain which should lead defrosted water onto the compressors lid (where it should be evaporated). This dirt holds some water in the drain after defrosting. By frosting again, this builds up ice layers in the drain until it is clogged. The periodically heating is not strong enough to defrost it anymore, because the ice extends deep in the drain. Now all defrosted water stays around the freezers evaporator and forms a big ice block. Finally the air circulation behind the rear panel brakes down and the frozen goods in front of the rear panel are getting warmer. The air sensor gives an alarm.

To solve this problem, you can easily turn off the device and wait for one or two days. All defrosted water will flow out of the freezer and everything (except your parquet flooring) will be fine after that. If you don't have the time, because you have the drawers filled with goods that may spoil, you have to remove the rear panel and melt the ice with a hair dryer. But be careful not do damage the lokrings at the connections of the evaporator. There will be still ice in the drain, that you can remove by poking with a drinking straw in the hole.

With this solution, you will have this problem again, a couple of month later ... There is a better solution to the automatic defrosting problem, that will be described in the next step.

FYI:

• A healthy heating loop has a resistance of 285Ohms, which corresponds to 185Watts heating power.
• The automatic defrosting runs periodically about every 8,5 hours for about 20 minutes.
• The fan only runs, if the door is closed and temperature of the evaporator is low enough (it makes no sense to fan frozen goods with warm air).

The Problem with the defrosting system is, that it is not guaranteed, that all ice is melted by the heating. Obviously the system is designed to work well for a new and clean freezer, but when it is getting older and accumulates dirt, then the function is not secured. The workaround from the Liebherr service is to to delay the temperature measurement and by this realize higher real temperatures during defrosting. The delay is realized by a coating consisting out of 3-4 layers of heat-shrink tubing around the sensor head. The sensor head should be mounted on top of the evaporator between the two aluminum connection pipes (and not at original position in the bottom near the heating strands).

The images show a replacement sensor with corresponding cable box installed additionally.

If you want to use the original sensor, be careful, when you pull the evaporator forward - do not exaggerate! And never rotate the evaporator - the lokrings will be damaged easily.

This time, we had no automatic defrosting problem - it was a real cooling problem.

At that time, we weren't yet able to check the pressure of the cooling system, so we started with some simple repair attempts. At least for us this was the next step. With the information given, you may skip this step and the visit of the service technician. This information should enable better decision making, which investigation should follow next.

We checked the operating capacitor. The capacitance was only 3 instead of 4 uF. But the replacement was unsuccessful.

We checked the starter. The PTC showed burn marks. But the replacement was unsuccessful.

We checked the compressors winding resistances. But they seemed to be normal.

We checked the main PCB. The triacs were not shot and the main electrolytic capacitors preserved their values.

FYI:

• There are 2 resistance loops for valves with the resistance of 5kOhms.
• There are 3 resistance loops for fans with the resistance of 3,5kOhms.
• The blue junction connectors were used for the logging of the defrosting system.

With the information given in this instuctable, you will not need the visit of a service technician. This step describes only, what we learned from him.

The Liebherr service technician told us, that 80% of his visited freezers have the automatic defrosting problem described above. He told us of a solution, that was described in step 3.

Up to 10% of the visited freezers have leakages in the cooling system. He checked it by removing the interior of a wine compartment and then he pressed his flat hand against the rear panel, which produced a hearable sigh - a gas flow that came through the small and open holes of the removed screws.

His judgement followed immediately: this device is not repairable! The refrigeration meanders have leakages. They are covered with expanded polyurethane foam in the back of the device. He would not try to repair this - even when this device would belong to him. He had friends who tried such a repair - but the result did not work for too long. A problem would be, that cooling cycles give mechanical stress to the refrigeration meanders and that leakage may be spread over regions with mirco-cracks arisen over years.

He told us, that we may find a used freezer device on ebay (but the registered search yields no results until now).

This device series is still in Liebherrs product range. For design reasons, you have to take left and right side and end up with a list price of 6000€. Liebherr offered us a goodwill price of 4200€ generously - but this is almost street price - and with our device still having a proper look - no option for us.

Ok, your Liebherr freezer is doomed. Now you are free, to have a look in the back and see what is going on below the polyurethane foam. You can cut the foam with a knife, but be careful, there are capillary tubes at the port side you may damage when acting with too much force.

We saw, that the refrigeration meanders apparently made some movement, because of the black greasy traces on the aluminium plates and the heat-conducting paste, that went out of place. The embedding foam is very rigid, so this might be a problem for the aluminium meanders.

At this point, we made our decision to go all the way - replace the meanders.

If you want to also do that, separate the freezer from the refrigerator and remove the doors (this is described in the user manual). Bring the freezer in a stable horizontal position (e.g. put it on two ale-benches) and protect the front with a soft coverage. If you don't want to reinstall the condenser, you can bend it back carefully (45°) and fix the position with an improvised rack.

Now you can uncover all meanders and clean everything.

Try to locate the problem by examining the tightness of the pipe system.

We used nitrogen and leak detection spray on all suspicious parts, especially the lokrings. We found a leaky one at the meander of the lower wine compartment (see attached video). But we were not sure, if this leakage was caused by bending during the uncovering.

With still the service technicians story of spreaded micro-cracks in mind, we continued in replacing the meanders.

The diameters of the pipes depend on the surrounding installation and on the connectors you can get. For the main meanders we used 8mm copper pipes. It is a good idea to use a special bending tool. While hard soldering, always flood the structure with nitrogen. Then you won't have oxide layers in the structure. Finally check the structure for leakage with pressure before inserting in the freezer.

... no, don't do that. We were inexperienced and thought, that it would be a good idea to be able to see, what is going on in the system and if it is "dry". But at the end, we could not get any valuable information out of it. If you like to do it nevertheless, install it in a vertical position, so you can see the gas stream by bubbles in the fluid.

In any case you have to replace the dryer and this means, that you have to open the connection near the lower valve (then it is easy to also add an inspection glass).

You can use almost every dryer. Take care, that the pipe dimensions fit and that the replacement is minimum as big as the old one. For further inspections a dryer with an additional SAE-connector should be used.

Having replaced the meanders and the dryer, check for leakage again (we checked with 7 bar over one night). If no pressure loss occurs, you are able to refill the system.

For this you have to generate a vacuum in the cooling system. This also removes any remaining moisture out of the system, because it evaporates and then it is pulled outside. After that, you can fill the refrigerant. The whole procedure is well described in a Secop/Vulkan Video.

Afterwards, we had the problem, that the device was not cooling at all. Only the lokring near the lower valve got cold. This was a hint to a diameter reduction inside the lokring, After cutting it out and having an optical inspection, it was apparent, that we applied too much sealant fluid "Lokprep" - always be frugal with that. We were lucky, that the ring was not closed entirely. In that case, the problem would have not been to find so easily.

The valves connection stub was now to short for a new lokring, so we had to insert a copper tube and solder it. Again: while hard soldering, always flood the structure with nitrogen. Additionally cool the valve with a wet cloth and while soldering, inject new water onto it.

Further leakage and function tests were ok.

Apply heat-conducting paste between the aluminium plates and the meanders generously. Then use a duct tape with great adherence for fixing the meanders. Cover them with a foil and fix the foil. Apply polyurethane foam. In the lower sensible areas use permanently elastic foam (in the images: blue). Fill the space with old or new polyurethane plates and press them down to prevent elevations. Fill the higher areas with rigid foam (in the images: green). Cut overhangs and seal with aluminium tape.

The device has to be filled with 52g of R600a originally. But we changed the volume with new meanders and added an inspection glass and added pipe volume. To calculate the difference, you have to take into account varying temperatures and pressures in the different added areas. We calculated 65g. But even with this estimate, we had the problem that such a tiny mass is hard to weigh because of the hoses producing force in all kinds of directions when they are under pressure. The result was not satisfying - the device was running all the time and the cooling was poor.

Pros are able to judge the values at the high and low pressure connections - but we had no reference for this device.

So we had to follow another strategy. You can feel the temperature on the condenser with your hand. It should be warm homogeneously. If the mass of the filling is wrong, then you will have a cold or a only-on-one-half-side-warm condenser. The power consumption should be low. You can see this in a power trace. There should be enough off-time (the image shows this for a hot summer day (additionally you are able to see the defrosting cycles every 8,5h)). We experimented with the filling quite a while and ended up with -0,84 bar pressure on the suction side and had a great cooling function.

The resurrected freezer runs now for one year without any problems. The side-by-side combi is still in a good condition. This may be due to a good mechanical housing quality of the device. On the other hand we know now, that the technical insides are just average. There are even some construction deficits as cheap/inferior lokrings, the unlucky mounting and fixing of thermally moving meanders in rigid foam  and a wrong parameterized defrosting system. The resulting problems are pushed by Liebherr to the user. This is not ok.

In the meantime we had a closer look at the old meanders with a microscope. It showed a normal aluminum surface - no wear - no micro-cracks. We don't believe in this spreaded micro-cracks story anymore.

If you have a problem with refrigerant loss, remove the foam in areas of the lokrings where the capillary tubes leads into the expanding pipes. Check and replace the lokring if necessary and then refill the system. We bet, in most cases you'll get rid of your problem.

At least we learned a lot from this project and the next two projects with refrigerant technology (our heat pumps) have passed in the meantime. But this would be another instructable.