Hi, I what to change my thermostat... the old one was a potterton prt100 st and the new one is a salus rt500.
At the potterton prt100 st I have 3 wires :
Blue is in 4 - N
Red is in 2 - H
Yellow is in 1 - TL
At Salus rt500 I have
L and SL no N.
Can you please tell my what wire goes in L and...