ST620RF INSTRUCTION MANUAL34
BATTERY STATUS
The ST620RF checks the battery voltage frequently during normal operation. If the battery voltage
is sensed as being low, the low battery indicator will be displayed on the screen. Although the
programmable thermostat will continue to operate normally at this stage, you should replace the
batteries as soon as possible to prevent the ST620RF entering OFF mode.
OFF MODE
The Low Battery indicator will be displayed if battery voltage is detected as “low”, in this case
the thermostat functions normally during battery low except the backlight is turned off. The ST620RF
will enter into OFF mode if the battery voltage falls drastically low, and all outputs will turn off.
As all functions except sampling the battery voltage are disabled in OFF mode, it is recommended
that you replace the ST620RF batteries as soon as possible to restore normal operation.
If the voltage of the replaced batteries is not high enough (if older batteries have been used) the
unit will remain in OFF mode and will not reset.
BACKLIGHT
The backlight of the ST620RF is switched on automatically whenever the Touch Ring is activated, or any of the keys are
pressed. The backlight will remain illuminated for approximately 6 seconds after the last key press, except if you are
changing settings within the Clock, Programme or Temporary Override modes – in this case, the backlight will remain
illuminated for 10 seconds after the last key press.
The backlight will not illuminate if the ST620RF battery is low, or if the Slide Switch is in the LOCKED position.
