This article is written by longtime tech Shaun McCann sharing his experiences with a big problem in our trade. Thanks for this, Shaun.  I started in the HVAC business working for a small commercial union shop in the late '80s. I left that job within a year and worked in the bar and restaurant business […]

Relays can be used for many different control applications, including controlling fans, blowers, other relays, or contactors, valves, dampers, pumps, and much more. A 90-340 is a very common, versatile relay that many techs have on their truck. So, we will use it as an example. A relay is just a remotely controlled switch that […]

Jim Bergmann and I recorded a podcast for HVAC School that covered when and how to check the refrigerant circuit without connecting gauges. Listener Joe Reinhard listened several times and wrote up this summary of what he gained from the episode. I edited it lightly, but most of this is his work. Thank you so […]