The commonest fault on these Siemens and Boss wireless thermostats is the failure of the JQX-118F relay in the receiver in which case the amber relay light will turn on but your boiler will not fire.

I will supply you with a JQX-118F relay or a branded equivalent. This needs soldering onto the PCB; not difficult if you've used a soldering iron before.

Please note that replacing the relay will not fix your thermostat if the problem lies elsewhere.

If you buy this you will receive a relay. YOU WILL NOT RECEIVE A ROOMSTAT OR RECEIVER!