I have question to connect Themstat to Humidifire.
Control board “C” to Themstat “C”
Control board “R” to Themstat “R”
Themstat “U” to Humidfiier “Blue” (total 2 blue wire as the inferface)
Themstat “U” to Controlboard “Humidifire”
Question is
Another blue wire from Humidfire to go “C” or “R” on Controlboard ?