76
replaced. The electronic board is faul-
ty.
In the case of a sudden lack of voltage, the
burner will immediately switch off. When
voltage returns, the boiler will automati-
cally start up again.
3.8
HEAD AVAILABLE
TO SYSTEM (fig. 14)
Residual head for the heating system is
shown as a function of rate of flow in the
graph in fig. 14.
The speed of the modulating pump system
is set as default (installation parameter
PAR 13 = Au
).
0
400
800
1200 1600 2000 2400 2800 3200 3600 4000 4400
4600
1011 1004
998
981
947
916
843
722
590
477
348
233
172
Flow Rate (l/h)
Residual head (mbar)
0
200
400
600
800
1000
1200
0
250
500
750
1000
1250
1500
1750
2000
2250
2500
2750
3000
3250
3500
3750
4000
4250
4500
4750
5000
RESIDUAL HEAD
(mbar)
FLOW RATE (l/h)
Fault finding
Fault
Cause
Remedy
1. Pump is not running. No
power supply.
• System is switched off.
Check the system controller.
• A fuse in the installation is blown.
Replace the fuse.
• The circuit breaker has tripped.
Check the power connection and switch on the circuit
breaker.
• Power supply failure.
Check the power supply.
2. Pump is not running. Normal
power supply.
• Controller is switched off.
Check the controller and its settings.
• Pump is blocked by impurities.
Remove impurities. Unscrew the deblocking screw at the
front of the pump. Deblock the pump from the front of the
control box with a screwdriver. Be aware of splashing hot
water.
• Pump is defective.
Replace the pump.
3. Pump runs at maximum
speed and cannot be
controlled.
• No signal from signal cable.
Check if the cable is connected to the controller. If it is,
replace the cable.
4. Noise in the system.
• There is air in the system.
Vent the system.
• Differential pressure is too high.
Reduce the pump performance at the pump or external
controller.
5. Noise in the pump.
• There is air in the pump.
Let the pump run. The pump vents itself over time.
• Inlet pressure is too low.
Increase the system pressure or check the air volume in
the expansion tank, if installed.
6. Insufficient flow.
• Pump performance is too low.
Check the external controller and the pump settings.
• Hydraulic system is closed or system pressure is
insufficient.
Check the non-return valve and filter. Increase the
system pressure.
