FAULT
CAUSE
SOLUTION
The safety valve keeps opening.
Problem with CH circuit safety valve.
− Check valve setting and efficiency.
Circuit pressure too high.
− Check circuit pressure.
− Check pressure reducer.
Problem with CH circuit expansion
vessel.
− Check efficiency of expansion vessel.
Reduced supply of domestic hot
water.
Supply pressure is too high.
− Fit a pressure reducer.
Lime scale and/or sludge in storage
cylinder.
− Check and clean.
Flow rate too high.
− Fit a flow reducer.
− Check functioning of DHW circuit
pump.
− Check positioning of sensors.
− Check boiler operating temperature.
− Check temperature setting of thermo-
static mixer valve.
− Reduce the speed of the solar circuit
pump first. Then turn the flow rate
adjustment screw on the valve group
to set a flow rate of 30l/h per m2 of
collector area.
Solar controller needs reprogram-
ming .
− Make sure that the
∆
T between the
collector and the storage cylinder is
not too high or too low. Set a
∆
T of
8-10°C.
Solar heating system inefficient.
Air in circuit.
− Bleed the circuit.
Flow rate too low or too high.
− Check that the flow rate is about
30l/h per m2 .
Pressure is low.
− Check that the cold pressure of the
system is approximately 3 bar.
The solar circuit pump does not
work, even if the collector tempe-
rature sensor detects a temperatu-
re higher than that in the storage
cylinder.
Maximum temperature has been
exceeded in the collector or in the
storage cylinder.
− Solar controller has reached maxi-
mum temperature and stopped the
pump. The pump will start working
again as soon as the temperature
drops in the collectors.
No electrical power.
− Check the safety devices and electri-
cal connections.
Temperature differential too great
for pump to operate, or controller
not working.
− Check the controller and the tempe-
rature sensor, or reduce the tempera-
ture differential setting.
The storage cylinder loses a lot of
heat overnight.
There is natural circulation to the
collectors.
− Make sure that the non-return valve
is sealed and closes properly. Replace
if necessary.
54
TECHNICAL ASSISTANCE SERVICE
