Heating Pump Cycling At Closed Valve

This function can significantly save electric energy.

If the calculated mixed water temperature setpoint is higher than the calculated room temperature setpoint "CalcRoomTmpSp” the valve will be closed and the heating pump can be temporarily switched off.

When the heating valve is closed for a time period longer than HPU-02 (switch off delay heating pump – time in which the pump continues to run at closed valve), the pump will be stopped for a time as defined by the parameter HPU-03 (period to restart heating pump). After the pump was switched off for the time HPU-03, it will be restarted to to avoid measuring the temperature in standing water. When the pump restarts it will run again for a minimum time period defined by HPU-02.

When the valve opens the pump will be switched on immediately.

When the parameter HPU-03 is equal to “0”, the pump will continue run as long as the pump switch on conditions are true – see chapter Pump Con trol. And the cyclic operation will be disabled.

Table 10.   Parameter List

Description

Value Range

Default Value

Unit

HPU-02: pump switch off delay

0...3600

300

sec

HPU-03: pump restart when valve closed; 0 = disable

0...7200

900

sec