Tech Tips

There is a lot of misunderstanding about the HSO (hard shut-off) or “non-bleed” TXV (thermostat expansion valve) and what makes it shut off, why it exists, and how it “magically” opens. Once you understand the forces inside the valve, it is quite simple, obvious, and sadly devoid of any magic. The Three Forces  The TXV […]

WARNING: This article contains spoilers for Die Hard (1988). If you’ve never seen the film and want to avoid spoilers, I suggest skipping this one or watching the movie first before you read this Christmas tech tip.  Here’s a fun thing to do at Christmas dinner: start the debate as to whether Die Hard is […]

My goal in this tech tip is to help those who struggle to understand heat pumps get their heads around them as quickly as possible and understand some of the things a tech needs to know about them. The basic idea of a heat pump is to use the compression refrigeration cycle to move heat […]

In these tips and on the podcast, we talk a lot about the importance of deep vacuum. Pulling a deep vacuum using proper processes and tools is really the ONLY way to ensure that a system is clean, dry, and tight. Just for review, that means: Nitrogen purge, flow, and pressurize > Cores removed > […]

I know, I know. You came here for HVAC content, so why are we talking about pool heaters? Since we live in Florida and don’t have that much of a heating season, we have to look for other forms of work during the winter months. Pool heaters fit the bill quite nicely since they’re actually […]

If you’ve been following my writing for the last couple of years, you know that I like to blather on and on about combustion analysis. Now, I am by no means an expert on the subject, as I live in North Texas (which is not known for its intense heating season), but I love using […]

I’d like to give special thanks to Roman Baugh for the section about compressor superheat. It’s not something we talk about very often outside of chiller and commercial refrigeration applications, but it definitely has value in the HVAC world as well. Thanks, Roman! Since I started in the trade, we would take discharge line temperature […]

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 […]

We’ve entered that season of service calls for “smoking heat pumps,” and I figured now is as good a time as any to share a few quick tips for troubleshooting defrost. Of course, the “smoking heat pump” calls can be solved over the phone with a quick explanation of normal defrost conditions—as can the service […]