21
Malfunction
Shower runs for a short
time (30-60 seconds)
then flow reduces,
splutters or stops.
Aggravated when other
hot taps are in use. Less
evident on full cold.
Flow of water virtually
stops and surges on/off,
after a few minutes.
Shower runs cold after
5-10 minutes.
Shower temperature
affected by use of
adjacent hot/cold tap.
Pump does not operate.
Pump does not stop.
Cause
Air is being sucked down
the vent pipe, as the hot
take off to the shower is
too high up the pipe.
Insufficient storage of
cold water in cistern.
BS6700 recommends
230 litres.
Insufficient storage of
hot water in cylinder.
Insufficiently sized
pipework for both
systems to be used
together.
Electrical supply failure
Micro-switch failure.
Pcb failure.
Motor overheated,
thermal switch operated.
Micro-switch defective.
Pcb failure.
Remedy
Refer to system diagram
section
“INSTALLATION
REQUIREMENTS”
for
correct connection
method.
Note the 1 metre hot
takeoff dimension.
Consider increasing cold
feed pipe to hot cylinder
to 28mm diameter.
Increase storage of cold
cistern.
Increase storage of hot
water.
Increase pipe sizes or
separately feed shower.
Refer to system
diagrams section
“INSTALLATION
REQUIREMENTS”
for
correct connection
method.
Check power supply.
Renew.
Renew.
Allow motor to cool
before further operation.
Renew.
Renew.
