Why is it called single-phase 240 when there are two opposing phases (or legs)? I wondered why we called two 120v opposing legs “single-phase 240” for years. Then someone pointed out to me that a typical “single-phase” pole transformer only has one power leg entering and two coming out. That freaked me out. How can […]

This gas furnace maintenance procedure in this article was developed by Michael Housh. Michael is the owner of Housh Home Energy in Ohio. He regularly works on natural gas equipment and is an active contributor to the HVAC School Facebook group. Thanks, Michael! Gas-fired equipment has a different set of components than your typical straight-cool […]

I was fresh out of school, working as an apprentice at my first real HVAC job, and I was listening in on a shop conversation between a few techs. They were talking about finding so many overcharged systems. One of the techs turns to me and says, “I had a unit yesterday that was so […]