After over a year of more or less trouble free Evohome living, the system has started to throw problems with the CS92 wireless thermostat for the hot water.

Every so often there will be a period where the controller shows a comms error with the sensor, and this may be anything from a few minutes to a few hours. Take a battery out of the sensor and pop it back in and the temperature is immediately displayed on the controller again. Ive tried changing batteries and even repositioning the CS92. There is now only one wall between the CS92 and the controller. A signal test shows either excellent or good communication.

Works fine for a while (anywhere from a few hours to a day), and then the comms errors start again. This causes major annoyance when it occurs just before the hot water is set to heat ready for showers on the morning. Cold water on the morning the missus is up early to wash hair is not the best way to start a day I can tell you.

I cant think of any changes in the room that would interfere with the comms, and certainly not at the random times the errors occur. The signal strength is fine when doing a test, either four or five flashes on the CS92 and excellent or good on the controller. A simple remove and reinsert of either battery and its all back and running fine again.

Can anyone think of anything that I may be able to check as to why this has started? Hot water has been fine for months on end until now.