In residential air handler/fan coils, it is common to use a high-voltage interlock between the blower and the electric heat strips to ensure that the blower comes on whenever the heat is on. The problem is that it CANNOT work the other way around where the heat comes on with the blower. Heat strips are […]

This article was inspired by a podcast episode featuring Jeremy Smith. Jeremy is a refrigeration mechanic and has contributed a lot of good material to HVAC School. You can listen to that podcast on floating suction and head HERE. Those of you who drive your own vans are probably all too familiar with the following […]

I got this question via email (edited slightly for length): Some things I've done because I've been taught to do them yet I don't know why I do them. One of those things is putting a jumper between w1/e and w2. Sometimes, in the case of a Goodman for example, I've been taught to combine […]