In the last 4-6 weeks the AC and heating unit has developed a problem and shuts down after a few minutes running time. The error code on the SMXii controller is “LO PS.” FYI, it shuts down and displays LO PS in both heating and cooling modes.
It’s my understanding the SMXii HI PS error code indicates a lack of cooling water through the system, and the LO PS error code indicates a lack of air flow through the system. I’ve cleaned the air intake filters, and the coils look relatively clean. I’ve not checked the freon level as I don’t know the pressure spec and procedural steps to do this.
If anyone has any suggested troubleshooting steps to resolve this problem it will be greatly appreciated.
Thanks to all for your help and may you have a Merry Christmas and a happy New Year.