The most common diagnosis with expansion valves is failed closed or restricted, resulting in underfeeding of the evaporator. The symptoms are low suction, normal subcooling, and high superheat when a TXV fails “shut,” but there are some other issues to watch for that can actually result in overfeeding the coil. Schrader in the Port The […]

This article was written by senior furnace tech Benoît (Ben) Mongeau. Ben hails from the frozen tundra of Ontario, Canada, where high-efficiency gas furnaces are commonplace. While some codes and practices may be different from the US, I find that most of it is common sense and translates pretty well. One glaring difference between Canada […]

I used to call PTCR devices a "Soft Start". I was wrong.