Tech Tips

We've seen it before. A tech diagnoses a failed blower relay or board. They leave the blower jumped out by putting a terminal multiplier on the common terminal of the relay/board and connecting the fan speed tap right to power. There can be an issue with that. Some electric heat fan coils have a heat/blower […]

There are several types of ice machines, but in this article, we will focus on cuber style and flaker or nugget style. Both types produce ice, but the process of freezing and harvesting is a little different. The application in which the ice will be used will determine what style of machine is needed. I […]

My good friend and contributor to HVAC School, Neil Comparetto, made this video showing how he creates access ports for static pressure and gas combustion analysis. As techs, we find ourselves in the tough position of needing to drill access holes to take measurements, but the drilling and sealing of the holes can sometimes create […]

This article is the second in a series on boiler basics by senior boiler tech Justin Skinner. Thanks, Justin. There are many types of boilers that do many different things, but almost all of them have some of the same basic components. It's partially because regulatory agencies require them, and other times, it's because they […]

This series of articles is written by senior boiler tech (and all-around swell guy) Justin Skinner. Thanks, Justin. There are quite a few different types of boilers out in the world. They come in all shapes, sizes, pressures, and types of fuel burned. I'm going to go over some of the more common ones, their […]

This article was written by Christopher Molnar, a licensed Florida mechanical contractor. While I'm not personally a practitioner of the “check static every time” doctrine, I certainly appreciate Chris and his passion for this topic. Thanks, Chris! Why Check Static Pressures on EVERY call You wouldn't go to the doctor’s office and walk away without […]

You may not know this, but the HVAC School podcast began before the website. When I started the podcast, I never intended to create a website, but there was more demand for quick tech tips than the podcast could hold. So, we started hvacrschool.com. In the same way, I never set out to create a […]

Double traps are no good. That's the end of this tech tip. Okay, here's some detail: Anytime your drain goes up and down more than once, you have a double trap UNLESS you place an air vent between the two traps that vents ABOVE the drain inlet. The double trap causes drainage issues because air […]

Photo by Brad Hicks at HVAC in SC Right off the top, let me state something loud and clear: The tool does not make the tech. Let that sink in before you move on. A good tech has a solid understanding of WHY they are doing what they are doing, the basic math of the […]