New Thermostat Honeywell (Homeexpert) THR870C
Old thermostat Drayton RTS-1
I have three wires poking out out my wall, appears Honeywell is a two wire unit.
Wires are blue, brown and yellow+green.
http://www.homexpertbyhoneywell.com/Documents/EN%20Manuals/THR870CUK-EN-d05.pdf
I...