"markkd" wrote in message
...

I wish to replace an old Sunvic room thermostat controlling the coal
fired central heating system. I have purchased a SUNVIC TLX 9201
thermostat. The existing wires are red, yellow, blue & yellow/green.
The new thermostat has 4 connection points.(ie: they are numbered
1,2,3,4) Could someone please guide me as to where these wires should
be placed-cheers!

In the UK? Do you know what the wires do?