Heating/cooling operation
The circulation pump (GP13) only runs in cooling mode.
The factory setting for the circulation pump speed is
MAX.
During heating operation (default) the mixing and re-
versing valves are closed as illustrated.
10
0
0
10
0
10
10
0
Shuntventil
Växelventil
Shuntventil
Växelventil
Värmeläge
Kylläge
Mixing valve
(QN18)
Reversing valve
(QN12)
When the reversing valve is open as illustrated below
cooling is activated. The shunt opens and closes depend-
ing on temperature.
10
0
0
10
0
10
10
0
Shuntventil
Växelventil
Shuntventil
Växelventil
Värmeläge
Kylläge
Mixing valve
(QN18)
Reversing valve
(QN12)
When cooling has been activated, heating operation is
blocked for two hours (factory setting) to prevent self-
oscillation between cooling and heating. If necessary,
the setting can be changed in menu 1.9.5.
PCM 40/42 | GB16