Solstice Fridge Cassette – Reliable Cooling Solutions

The Solstice Cassettes are quite robust but some conditions may cause them to function incorrectly or not at all like most refrigerators. Before going through this it is desirable that you have the manual with you and have looked at how it should be installed, set up etc. Here are some basic steps to check if a cassette is working correctly or not:

• Please ensure that there is power to the unit. Power will be from the power pack supplied with the unit or a 12 volt cable connected to a suitable 12 volt source (strictly observe polarity if making your own). Once connected the controller LED display should be displaying its Temperature. If there is no display then please check that the power pack or 12 volt supply is working. This can be done with a simple multimeter. If the power pack or supply is not working then this will need to be changed.
• Having the display light up we can now check the parameter setting. Please read the manual on how this is done. The parameters should be set as follows in the Table below under the Normal Setting heading. Where longer defrost is desirable set as per the next column. The letter x indicates “don’t care”. The last column is for settings where lower temperature are set and prevent the alarm indication.

• Once the parameters have been correctly set and the desired temperature has been dialled in we can see if the unit is calling for cooling or heating (depending on which is selected). Top left LED indicates its set for cooling and bottom left is for heating.
• In cooling mode we should see the cooling indicator come on after the compressor delay time. This will be normally 3 minutes and should never be set to less than 2 minutes. Once this LED comes on please check that the compressor is running (you can touch it and feel it vibrating and also it makes a low whirring sound). Also both fans should come on if not already running.
• Normal operation results in the air coming from the top fan cooling down and you should also see the temperature indicator on the controller coming down. Because its not recirculating fridge air it may not come down much but there should be a change. Also the compressor should be getting warm.
• If the compressor or the fans do not come on when the unit is operated from scratch in this scenario then there is a fault.
• There is another scenario where the fridge has been operating for some time but no longer cools down fully. It will hover around 10-14 degrees and this is a good indication that the evaporator coil has iced up. Please see the following instructions.

With the Solstice Cassettes now being in use for almost two years we find that they are generally quite reliable and if operated correctly do not have issues.

Nearly every unit which has a problem reported ends up being related to the fact that the evaporator coil can become iced up if there is too much moisture in the air. Generally it can happen very quickly if the door is left open for long periods or it can build up over time lulling the operators into a false sense of all being ok.

Due to its compact design the evaporator coil has to get quite cold to function effectively and this of course means that ice can form easily if there is moisture in the air. For that reason the controller does have a defrost cycle which periodically activates the heating system to clear the surface ice that it can be expected to build up. We do see some operators turning the defrost off and that is of course not advisable. We also see operators setting the temperature down to 0 degrees which of course it can achieve but it is not really desirable to serve beer at such low temperature (easy to get frozen beer lines that way also). Usually a setting of 2 degrees should be adequate. We also recommend the hysteresis to be no less than 2 degrees but preferably 3 degrees. This setting determines how many degrees the air temp in the fridge will rise before the compressor comes on and drives the temperature to 0 again.

So usually if in doubt set the controller back to its default with a factory reset. You will find how to do this in the manual supplied with the fridge.

Unfortunately not many people have a good understanding of how a fridge works and tend to think a beer fridge is like the kitchen fridges in most homes. Kitchen fridges are designed to be able to handle the frequent opening and loss of the cold air inside. Beer fridges on the other hand should really only be opened when a keg is being changed. 

What to do if your cassette based fridge only cools down to somewhere between 10-14 degrees? This is usually the giveaway that the evaporator coil has iced up to some degree or even completely. Here are the steps you can take to overcome the problem:

1.     Unplug the cassette and using a Phillips head screw driver carefully undo the 6 screws holding the cassette in situ. 

2.     Remove the cassette from the fridge.

3.     Examine the evaporator coil which is located behind the fan towards the upper part of the cassette. If the ice had built up so much that it touches the fan blades then you might have heard a whirring sound when the fan was operating. In severe cases the ice can stop the fan from rotating.

4.     Using a torch or phone light look past the fan blades to see if ice is present and if so how much. Because the chamber in which the evaporator coil is situated is very well insulated it can be quite difficult to remove this ice. DO NOT USE ANY SHARP OBJECTS to scrape any ice away. This can only be done by warming the unit. Sharp objects could damage the coils and release the refrigerant.

5.     The ice can build up into a solid block which may take several days to melt by itself. If the cassette is still in the fridge it will of course take longer.

6.     The best way to remove the ice is to face the cassette evaporator fan to strong sunlight  or use a fan heater to direct a stream of warm air towards the coil.

7.     If in doubt about being able to see ice you can cut the pointy end off a 25 cm ZIP tie and gently push it through the vanes of the evaporator coil. It should go through free and easy and not be blocked.

8.     If the ice deposit is not heavy enough to fully block the evaporator coil then you can set the controller to heating and run it that way for an hour or so and that will help clear the ice out.

9.     Melted water from the ice will make its way slowly past the kink in the ribbed tubing and end up in the evaporation tray above the compressor.

10.This operation may be done with the cassette installed in the fridge or not. For how to set the heating please see the manual.

So once the cassette is cleared of ice then the fridge should operate normally again. As mentioned before do not open the door any more than is necessary especially in humid, warm climate regions.

Without active intervention the ice can persist in the insulated evaporation chamber for the better part of a week and if not fully cleared will quickly make a comeback.