If you don't do a lot of commercial work, you may see a system like the one above and wonder what the heck it is. It is a 100% fresh air unit or a makeup air unit. You will see them more and more as codes start to reflect that balanced ventilation and conditioned outdoor […]

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 […]

So many techs are OBSESSED with how to set a charge rather than understanding all of the readings, specs, and system conditions that go into optimum system performance. Before “setting the charge,” I suggest (nay, I REQUIRE) that you do a full visual inspection of the system, have an understanding of the initial factory charge […]