Wilo COHe, Installation And Operating Instructions Manual

Page: 21 / 28

p. 21 4227862 ed.04
ATTENTION!
Do not let the pump operate with delivery valve closed beyond one minute.
8.3 Decommissioning the installation
If the booster has to be decommissioned for maintenance, repair or otherwise, it is necessary to proceed as
follows:
• Close the main switch and protect the installation against any inadvertent re-engagement.
• Close the shut-off valves before and after installation.
• If necessary, drain the system completely.
9 Maintenance
For optimum operational safety and the lowest possible operating costs, it is advisable to carry out regular
checks and maintenance of the booster set (refer to DIN 1988). For this, it is preferable to subscribe a
maintenance contract with a specialized company or our after-sales service. The following checks must be
performed regularly:
- Control of the operating order of the booster set
- Check the mechanical seals of the pumps. For greasing, the mechanical seals use water, which may leak in
very small quantities at the joint. In the event of a consequent leakage, the mechanical seal must be replaced.
For long-term decommissioning, proceed as described in section 8.3 and drain all pumps by opening the drain
plugs at the foot of the pump
ATTENTION!
Fill the pump before any new start.
10 Faults, causes and remedies
DANGER!
SWITCH OFF the booster before any maintenance or repair work.
Faults Causes Remedies
ONE OR TWO PUMPS FAIL
TO PRIME
Air leak at suction
Check tightness of tall suction pipe
connections.
Check if the suction strainer is covered with
water.
Foot-valve strainer not tight
or obstructed Check tightness of the check valve, replace
it if necessary.
Large losses of head at
suction Calculate the losses of head and make sure
they are compatible with the pump NSPH.
.
Public water pressure too
low or zero If it recurs, it is recommended to use a tank.
Suction head too high Make sure that the minimum water level of
the tank is compatible with the NPSH of the
pumps
Suction piping obstructed or
valve on suction manifold Check valve opening and clean the piping if
necessary.