Other functions
LCD backlight
• LCD backlight is activated when or any key is pressed. The backlight will be turned off in 15 seconds
after all keys are released.
• LCD backlight will not operate when battery is low.
Low battery detection
Battery voltage is checked every minute. When the battery voltage drops to a certain level, the Low-Battery
warning indicator appears.
• The thermostat functions normally during low battery. However, user must change the batteries as soon
as possible before the battery is too weak for the normal operation to be assured.
• When you change the batteries, you have about 30 seconds to to do so without losing your settings.
Temperatures outside operating range
Temperatures below 10 °C are displayed without the leading ‘0’. Temperatures exceeding the measurable range
will be indicated by ‘HI’ for temperatures above the upper limit, and ‘LO’ for temperatures below the lower limit,
as shown in the images.
18 RT310i Installation Manual