Hi, I today came across a fault Iv never experienced. I have a Daiken cassette split system on R410a. In heating, both the suction and discharge pressure rise very quick, both up to over 500psi. Eventually the unit detects a fault and the compressor cuts out.

When in cooling, both the suction and discharge pressures fall, the discharge pulls down into a vacuum, and the suction to around 5psi. Compressor doesn't sound at all healthy. However I don't see that being the cause. My first line of thought was a blockage somewhere. But usually a high discharge and low suction etc etc is a sign.

My next thoughts where to reclaim the refrigerant, weigh it out see if its correct. Disconnect refrigerant lines and make sure pipe work and evaporator coil are clear. Then push nitrogen through the outdoor unit and see the outcome.

Any help would be appreciated. cheers, Craig 