Introduction; Working Principle - Bosch HP270-2 Technical Manual

1) Introduction

Domestic Hot Water Heat Pumps (DHW-HP), with or without air connections ducts, use the heat existing in the
surrounding air, or the wasted heat from the indoor air, as energy source for DHW preparation.
This model of domestic hot water heat pump provides hot water for residential purposes, using a closed refrigerant
unit filled with R134a. This ensures the energy production taking out the energy from the air – the cold source –
and delivers the energy to a secondary circuit – the water – where a simple circulation pump, ensures the water
movement through a plate heat exchanger, heating the water that is stored in a tank.

2) Working Principle

There are 2 variants of heat pumps, depending on the working conditions:
- Positive working temperatures: +5ºC / +35ºC
- Negative working temperatures: -10ºC / +35ºC
Note: In case the air temperature is out of the specified working range, the appliance automatically activates the
electrical back up (if in Combi mode). One hour after the warning display (HOT or COLD) has appeared; the
appliance checks the air temperature and, in case it is within the range values, returns to heat pump mode
operation.
The control loop for air temperature check is done every hour, while the electrical backup is in operation.
Stand-by mode
HMI actuation
(default from factory = 50ºC)
(except FD>555: software
Page 2 from 56
LCD Backlight ON
Temperature Selection
7003/5003 = 54ºC)
6-720-821-364 SM HP270 – 250 - 200 2016/12 en
(after 15 sec without any selection)
Active Operation Mode
(default from factory: combi mode + manual operation)
Current Temperature of the Tank
(measured at the top)
Clock & Day Function
(defined at start up and/or current day and hour)
Temperature Blinks
until confirmation with
OK button
LCD Backlight OFF
Temperature remains as
previous after 10 sec in
case of any other selection