Matt, what are the key factors to consider when diagnosing a system short-cycling issue?

In this edition of “HVAC Skill Builder,” Matt discusses diagnosing a system short-cycle issue.

Matt, what are the key factors to consider when diagnosing a system short cycling issue? Well, some of the key considerations are going to be, number one is going to be a possible restriction inside the system. So if you have a system is operating, you have your gauges on and the head pressure go up and it shuts off, that typically is indicative of some type of restriction in the system. Now where that restriction is, it could be a bunch of different places. Number one, I used to start with a filter dryer to see if that was restricted. Take a temperature measurement rider crawl set, give one of the two degrees or an unlikely that filter dryer is plowed up. It could also be the service valves that are out of the unit or any type of metering device such as the THV or a fixed orifice on a system. So the key to finding that is taking measurements whether it’s temperature or pressure and going through the entire system. And so you’ve located that restriction.