We keep two-pole, 40-amp 24v coil contactors on all of our vans. They are versatile and reliable, and you can replace most residential A/C contactors with them. There are a few things to watch for, though, especially when you have a crankcase heater. Many brands power the crankcase heater constantly and shut it on and […]

Another follow-up article by Michael Housh… Enjoy! In this article, I thought I would show a pump curve and match it up with our system head-loss curve that we created in the last article, but before I do that, I thought I would talk a little bit more about the system head-loss curve and why […]

Time and time again, low-voltage wiring gets the better of HVAC technicians everywhere. Sure, the wires are color-coded, but that doesn’t mean they’re easy to understand. On top of that, schematics sometimes look like ancient tablets written in hieroglyphics or something. But that’s where HVAC School comes in. There is a new 3D animation video […]