Different Ignitor Types and How They Work
In the furnace sequence of operation, the ignition sequence happens after the safeties have been checked, the inducer fan comes on, and the pressure switch closes. The ignition sequence begins with the ignitor. This part provides the heat needed for combustion (remember: a fire needs heat, oxygen, and fuel), and the ignition process looks a […]
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The Enemy of My Enemy Is My Friend
As we get older, our understanding of the difference between good and bad—right and wrong—evolves. This understanding often first takes on the form of playing cops and robbers or superheroes and bad guys in our childhood. As we grow, especially as we navigate adolescence and adulthood, we apply the labels “good” and “bad” (or “friend” […]
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The VOCs Lurking Under Your Customers’ Sinks (and In Many Other Spots)
In HVAC, we have a few infamous indoor air quality monsters that bring terror to our customers’ homes—gases, particles, and organisms that wreak havoc on indoor air quality (and may contribute to moderate to severe health problems). The big one is carbon monoxide (CO), which we all know is deadly. Although not deadly by itself, […]
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Proper Liquid Line Drier Location
Diagram above by Carrier  It's really easy to put a liquid line drier in the proper location, but it's still more commonly installed in the WRONG location. Namely, people install it right at the condensing unit. (OK, it isn't that big of a deal, but I needed some dramatic emphasis.) Installing it at the indoor […]
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Gluing Tubing Insulation
I see a lot of techs and installers use tape over foam tubing insulation joints (Rubbatex, Armaflex, etc.) rather than using the glue that is designed for it. Some of them use tape because they don't know the glue exists; some use tape because it's what they happen to have on the truck, and others […]
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Another Ob-NOx-ious Combustion Product
As we do fall maintenance and head into the heating season, combustion analysis becomes a big deal. (It’s always kind of a big deal, but now it’s a really big deal.) First and foremost, it tells us how much carbon monoxide (CO) is produced by burning. CO can make people ill, contribute to cognitive deterioration […]
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Drains and Double Traps
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 […]
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How to Replace a Condensing Fan Motor
Service calls about condensing fan motor failure are quite common. Even though fan motor replacement is a standard procedure for residential split systems, it requires careful attention to safety and detail. This article will give you a step-by-step guide showing how to replace a condensing fan motor. Along the way, we will also explain a few […]
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Don’t Get Depressed (Unless You’re a Core)
This website is for professional HVAC techs and those actively learning to become professional HVAC techs, not DIY homeowners. I feel like that needs to be said before I state these seemingly obvious facts, but these very obvious facts are so commonly mistaken that they need to be covered. Take a look at the two […]
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