Grundfos ALPHA2 Series - Bypass Valve Operation; Operating the Product; Automatic Night Setback

English (GB)
17
7.9 Bypass valve
Fig. 29 Systems with bypass valve
The purpose of the bypass valve is to ensure that the heat from
the boiler can be distributed when all valves in the
underfloor-heating circuits and/or thermostatic radiator valves are
closed.
System elements:
• bypass valve
• flowmeter, pos. A.
The minimum flow must be available when all valves are closed.
The pump setting depends on the type of bypass valve used, i.e.
manually operated or thermostatically controlled.
7.9.1 Setting the bypass valve
7.9.2 Manually operated
1. Adjust the bypass valve with the pump in setting I (speed I).
2. Observe the minimum flow of the system. See the
manufacturer's instructions.
3. After setting the bypass valve, set the pump according to
7. Control functions.
7.9.3 Automatically operated, thermostatically controlled
1. Adjust the bypass valve with the pump in setting I (speed I).
2. Observe the minimum flow for the system. Consult the
manufacturer's instructions.
After adjusting the bypass valve, set the pump to the lowest or
highest constant-pressure curve. For further information about
pump settings in relation to performance curves, see section
9. Fault finding.
8. Operating the product
8.1 Using automatic night setback
Fig. 30 Automatic night setback activated
If you select speed I, II or III, automatic night setback is disabled.
You do not have to re-enable automatic night setback if the power
supply has been switched off.
If the power supply is switched off when the pump is running on
the curve for automatic night setback, the pump starts in normal
operation. See section 9. Fault finding.
The pump changes back to the curve for automatic night setback
when the condition for automatic night setback is fulfilled again.
See section 8.2 Function of automatic night setback.
If there is insufficient heat in the heating system, check whether
automatic night setback has been enabled. If yes, disable the
function.
To ensure the optimum function of automatic night setback, the
following conditions must be fulfilled:
• The pump must be installed in the flow pipe. See fig. 30, pos.
A.
• The boiler must incorporate automatic control of the liquid
temperature.
Enable automatic night setback by pressing . See section
7.5 Button for enabling or disabling of automatic night setback.
Light in means that automatic night setback is active.
TM05 3076 0912
ALP
A
HA2 L
AUTO
BYPASS
1
2
Q
min.
3
3
A
TM061251 2014
Do not use automatic night setback when the pump
is installed in the return pipe of the heating system.