Draw hot water at high rate
Does flow indicator (tap)
on display light up?
Yes
Check hot water flow rate and temperature.
Compare with technical data, if flow is not
sufficient, check incoming main and cold water
filter.
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
Does green warmstart
indicator flash now?
Check/Clear impeller in
Aquasensor, replace if necessary
Check/replace hall sensor
Replace electronic board
Does hot water indicator
glow/flash now?
Does green warmstart
indicator flash now?
No
No
Yes
Yes
No
Sheet GCheck D.H.W operation
Go to sheet B/C/E or F
Check DHW pump operation, is
230 VAC present across terminal
X601;
check/clear non return valve
and impeller on the pump;
replace the pump, if necessary
No
Is the boiler running?
Yes
Is the boiler running continously?
No
Yes
Normal operation carry out electrical safety checks
