CH121
5
INSERTION AND REPLACEMENT OF BATTERIES
Insert two AAA 1.5 V alkaline long lasting batteries, of a good brand, paying attention to
the marked polarities.
N.B. the life of the batteries is greatly affected by the type of use and the settings made
by the user, especially the set back lighting switch-on time.
When the batteries are low, the symbol of the discharged battery flashes on the
display:
. CH121 keeps working regularly, but the display does not light up.
If the batteries are completely discharged, the chronothermostat quits working,
switching off the system and disabling the keys.
“OFF”
together with the symbol of
the discharged batteries appear on the display until they are replaced.
To replace the batteries, remove CH121 from its housing, moderately pressing inwards
and at the same time on both sides of the cover.
All parameters remain stored while the batteries are being replaced.
COMFORT / TMAX
ECONOMY / TMIN
OFF ANTIFREEZE
QUICK GUIDE FOR PROGRAMMING
4
DESCRIPTION OF KEYS AND DISPLAY
The thermostat is equipped with 4 keys, the function of which varies depending on
the situation. It is described by the symbol which appears on the display next to the
key.
winter relay ON
summer relay ON
room temperature
Celsius / Fahrenheit
summer/winter
4 function keys
reset
function
3
