Bosch DOMESTIC HOT WATER HEAT PUMP Technical Manual page 34

The working principle is based in the following considerations:
Switch OFF
Switch ON (main switch in the back of HP)
1)
For Stand-by Mode
(1)
Stand-by mode
Temperature Selection
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No Reaction from system
Error in memory?
no
(1)
Stand-by mode
HMI actuation
Temperature Blinks until
confirmation with OK button
6720649497 SM HP270-1 2012/09 en
yes
Error Mode
LCD Backlight ON
Active Operation Mode
Temperature of the Tank
Clock & Day Function
LCD Backlight OFF (after 15
sec without any selection)
Temperature remain previous one
after 10 sec without any selection