Fault Finding - Grundfos PM Rain Installation And Operating Instructions Manual

12. Fault finding

Warning
Before starting work on the pump/PM Rain, make sure that the power supply has been
switched off and that it cannot be accidentally switched on.
Fault
1. The pump runs
continuously.
2. The green "Pump
on" indicator light is
on, but the pump
does not start.
3. The pump does not
start when water is
consumed. "Pump
on" is off.
4. Frequent starts and
stops.
5. The pump does not
stop.
Cause
a) Air lock in the system.
b) The pump cable plug is inserted
directly into the power supply socket.
c) Water is still being used.
d) Water is leaking on the discharge side. Check for leaks.
e) The start pressure is set too high.
f) The non-return valve is stuck in open
position.
g) The PM Rain is defective.
a) The power supply to the pump is
disconnected after the PM Rain.
b) The motor protection of the pump has
tripped due to overload.
c) The pump is defective.
d) The PM Rain is defective.
a) Too big difference in height between
the PM Rain and the tapping point.
b) The PM Rain is defective.
c) The pump cable plug is not inserted
into the PM Rain.
d) No power supply. No light in Rain
water or Mains water indicator lights.
a) DIP switch 5 set to "ON".
Note: For system without pressure
tank.
b) Leakage in the pipework.
c) The non-return valve is stuck in open
position.
d) The pressure tank has no precharge
pressure, or the tank size is
insufficient.
Note: For system with pressure tank.
a) The pump cannot deliver the
necessary discharge pressure.
b) The start pressure is set too high.
c) The PM Rain is defective.
d) The non-return valve is stuck in open
position.
Remedy
Release air from the system.
Open valves (taps, flush toilets, operate
washing machine) from nearest to
furthest outlet. Repeat, if necessary.
Insert the pump cable plug into the
PM Rain and the PM Rain plug into the
power supply socket.
Check all taps, toilets, and appliances
connected to the PM Rain to ensure that
they are turned off. If the pump does not
stop, switch off the pump, and check the
discharge pipe for leaks.
Decrease the start pressure.
See section 5.1 DIP switches.
Clean or replace the valve.
Repair or replace the PM Rain.
Check the plug and cable connections.
Check if the pump is blocked.
Repair or replace the pump.
Repair or replace the PM Rain.
Adjust the installation, or increase the
start pressure.
See section 5.1 DIP switches.
Repair or replace the PM Rain.
Check the plug and cable connections.
Contact an electrician, or restore the
power supply.
Set DIP switch 5 to "OFF".
See section 5.1 DIP switches.
Check and repair the pipework.
Clean or replace the non-return valve.
Check the tank precharge pressure, and
recharge the tank, if necessary.
If the size of the pressure tank is
insufficient, set DIP switch 5 to "OFF", or
replace the pressure tank.
Replace the pump.
Decrease the start pressure.
Repair or replace the PM Rain.
Clean or replace the non-return valve.
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