We may have found other answers which could help you.
Click here for Thermostat Turn 20is it possible to repair a non digital Drayton SM2 timer?
how can i fix thermostat?
Drayton Digistat+2 RF?
Drayton Digistat +RF Model RF-601?
Digistat Drayton connection?
how to replace batteries in my Drayton Digistat RF1?