Draw hot water at high rate
Yes
Check hot water flow rate and temperature.
Compare with technical data, if flow is not
sufficient check incoming main and cold water
filter.
Normal operation carry out
electrical safety checks
No
Check cold water inlet pressure is
sufficient and that cold water inlet
filter is clear
Check cold water inlet is fully open
and adjustment is at maximum
flow rate
Check/Clear impeller in
Aquasensor, replace if necessary
Check/replace hall sensor
Replace electronic board
Does hot water indicator
glow/flash now?
No
No
Yes
Yes
No
Sheet G
No
Check D.H.W operation
Does yellow hot water
demand indicator glow?
Does yellow hot water
demand indicator glow now?
Does yellow hot water
demand indicator glow now?