INSTALLING AND REPLACING BATTERIES
Installing or replacing the ST620 batteries is a straightforward operation, but does require you to
open the case of the programmable thermostat - always isolate the AC Mains supply before
opening the unit.
To open the ST620 case, undo the securing screw on
the bottom of the case (just to the right of the hole
for the Reset Button):
After undoing the screw pull it forward until the
screw stops moving, then carefully separate the
two halves of the case by gently pulling in an
upwards direction. Once the case has been
separated, the batteries should be visible:
Ensure that the batteries are inserted correctly, paying careful attention to the polarity markings on
the battery and next to the battery holders. After inserting the batteries, refit the ST620 case and
retighten the securing screw.
ST620 INSTRUCTION MANUAL6