Can you help?
I bought a Greenbrook 7 day timer to control my heating system.It has 2 red and 2 blue wires. On removing the old timer I found 2 red, 2black and 2 earth wires protuding from the wall. I fitted red to red, Blue to black and connected the 2 earth wires together. The timer does not work but if i turn the thermostat up to beyond room temp then the timer clock starts to work. If I turn it down below room temp it switches the clock off.