Fridge freezer refrigeration R600a gas system fault finding troubleshooting

When working on these system safety is the first priority. R600a is a flammable gas and precautions should be used when working on these systems, they do not hold much aprox 80 grams but still be careful when using and storing. Keep the room well ventilated when working on these systems and remember butane will settle to the bottom of a room being heavier that air.

If you suspect a problem with the system you can attach the gauge to take readings of the gases pressure to help with fault finding diagnostics. 

Healthy systems can have a  static pressure reading of between 0.5 - 3 bar , that is with compressor off and pressure equalised from low to high.

With the gauge connected to low side and compressor turned on you would expect to see pressures between -0.1 and -0.6 , negative because your on low ( suction ) side of compressor.

If when you turn on compressor the gauge does not drop into the negative this is a sign your compressor is faulty.

If the system pulls into a complete vacuum it could be a sign of the system having a blockage somewhere if it goes below -0.6 slightly its worth adding a tiny squirt of gas but more than likely the drier unit has become blocked. ( replace drier unit , vacuum system and recharge.) 

If you suspect a leak you can use an electronic sniffer to find R600a leaks quite easily, remember to turn compressor off for testing low side of the system and to turn compressor on for high side testing..