Danfoss RET2000 B Guide De L'utilisateur page 10

Low Battery Indications (RET2000B)
For battery powered thermostat (RET2000B) when the batteries
GB GB
require replacement the battery low symbol will ash. Batteries
should be replaced within 15 days, after which the thermostat
DE
will turn o the load it is controlling. If the power LED does
not illuminate when the dial is turned the batteries may have
DK
expired and should be replaced immediately to avoid damage
to the thermostat
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10 RET1000