Drayton Digistat Wireless Thermostat...please help!

Hi

I have a RF1 Drayton wireless thermostat. Went to change the temperature earlier and the display went blank all of a sudden, now its not working at all. The red receive alarm is on on the scr receiver and even when I press the overide button the green light comes on but still no heating. I have tried changing batteries but doesn't make a difference still no display on thermostat. Any ideas?! Thanks...

could be poor battery contact, try adjusting the shiny bits at bottom of battery comps to give better contact and make sure batts are right way up

Ive tried that but still nothing, surely if the green overide light is on then the heating should come on without the thermostat anyway but its not?!