Bosch HP270-2 Technical Manual page 54

Code EF6 – Lock Out Error (reset by pressing OK for more than 3 sec) (HP 200_250-1 / 270-3)
Detected an incorrect purge of system with E-heater in normal operation (detected by NTC T dis > 85ºC)
Air presence in hydraulic
circuit in module
Code E10 – Lock Out Error (reset by pressing OK for more than 3 sec)
Fault in the E-heater (detection by the current sensor in control unit: I < 6A)
Page 54 from 56
Activate PURG function in SET mode
Purge using manual air vent between
pump and condenser
(Attention: water will exit by valve and
precautions are needed to protect
surrounded components)
Thermal Cut out activated (safety
thermostat) due to over temperature
Reset thermostat manually
(measure also continuity
between terminals)
Problem persists?
Possible defective E-
Inspect reason for over-temperature
activation. Scaling may occur in areas with
hard water (refer to recommendation /
6-720-821-364 SM HP270 – 250 - 200 2016/12 en
(HP 200_250-1 / 270-3)
No
Yes
Heater –
guideline in installation manual)
Ensure that thermostat is really in
contact with e-heater copper pipe
End
Refer to spare part list
and replace it