Honeywell Rth221b Thermostat Wiring Diagram. March 4 2019 1 0. Hi folks i have a basic honneywell programmable electronic thermostat honeywell rth221b that i would like to use to replace the existing very basic and very old turn knob type thermostat in my apartment.
Lets take a look at the g wire. 5 wire honeywell thermostat wiring. One touch access to setpoint temperature.
Do not use b wire if you already have 0 wire.
I purchased one of these honeywell rthb thermostats to try it out but the instructions are pretty much useless and my wires coming out of. Honeywell thermostat wiring instructions for 4 5 wire applications. The ob wire can have many configurations. Rth221b thermostat pdf manual download.