09/23/2026
Called out to a humidifier that wasn’t working. Looks like whoever installed it mixed up the R and C wires from the furnace to the humidistat. When this happens it’s sending the 24vac of power to the wrong terminal on the humidistat which doesn’t guarantee a burned out humidistat but when left that way for a long time it can. Even after switching them, I still couldn’t get the humidistat to give a call for humidity. I even put the humidistat into test mode which should bypass the humidity sensor and just switch it on but still nothing. Now I know the humidistat needs to be replaced. Luckily this issue was such that it’s just the humidistat that got fried and not the furnace control board. Those are a lot more costly to replace.e