We may have found other answers which could help you.
Click here for Heating Repair Faulty
Drayton Digistat+2 RF?
How can I override code I can't remember?
How can I increase temp range on a DT20RF thermostat?
Drayton Digistat +RF Model RF-601?
is it possible to repair a non digital Drayton SM2 timer?
Drayton sm2 timeswitch?