When you work on a heat pump system and want to test defrost, you can follow many different test procedures to test the board and sensors. Most involve “forcing” a defrost by shorting out pins on the board or advancing the time of the defrost initiation and installing a factory-provided pin jumper. Lots of pins […]

The photo above is of a real condenser coil we cleaned just the other day. The outer fins looked OK, but dirt and lint were packed deep inside, and the head pressure and condensing temperature were sky-high. That situation illustrates that a coil can sometimes look OK at first glance but may still need to […]

This series of articles is one of those that will bug a lot of people because it will go against a lot of what you've been told about compressors, start capacitors, and inrush current. For that reason, I want you to work through a few thought experiments first and maybe even stop and try it […]