Riello KV/200 20 ISC Solar Installation And Maintenance Manual page 52

FAULT
Reduced supply of domestic
hot water.
Solar heating system
inefficient.
52
TECHNICAL ASSISTANCE SERVICE
CAUSE
Supply pressure is too high.
Lime scale and/or sludge in
storage cylinder.
Flow rate too high.
Solar controller needs
reprogramming.
Air in circuit.
Flow rate too low or too high.
Pressure is low.
SOLUTION
Fit a pressure reducer.
Check and clean.
Fit a flow reducer.
Check functioning of
circuit pump.
Check positioning of sensors.
Check boiler operating
temperature.
Check temperature setting of
thermostatic 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 m of collector area.
2
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.
Bleed the circuit.
Check that the flow rate is about
30l/h per m .
2
Check that the cold pressure
of the system is approximately
3 bar.
DHW