Hi, my name is ***** ***** I have been in the home improvement and repair field for 20 years. I will be very glad to help you today. Is this a new thermostat? If you bring it closer to the receiver does it function properly then? If that does not do it then if you bring the thermostat closer to the receiver then remove the batteries for ten minutes then replace them and then replace the thermostat does it work then?
no ten years old
it reads 22 degrees in the room but its far colder have changed batteries with new ones if i click to 23 the boiler fires up
Try the things suggested. It may not be getting a good connection and the connection just has to be reconnected. If it seems to work when it is closer to the receiver then it will either need to be moved closer or replaced. Ten years is about the life span of wireless thermostats. I am not saying for sure that it will need to be replaced but it is a strong possibility. It may just need the communication to be re-established.
If bringing it close to the receiver and removing the batteries for ten minutes then replacing the batteries does work but then placing it back in the wall plate it does the same thing it could also mean that the batteries are not strong. Were they new store bought batteries?
changed batteries severalties with brand new believe problem solved termo reset at 17 and boiler firing up