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- To carry out electrical continuity tests across the components make sure:
a) electrical supply is OFF and the multimeter is set to the
:
position,
b) the connectors of the component to check are disconnected
- During checks, verify the integrity of the wirings and their correct electrical connections
TURN THE MAIN SELECTOR TO THE POSITION “STAND-BY”
a) Is the
Has the main
NO
- Check the 230 V electrical supply circuit
green led
NO
electrical supply
flashing?
connector 230 V
YES
- PCB fuse blown
across L and N ?
- PCB faulty
YES
TURN THE MAIN SELECTOR TO “SUMMER”, SET THE HOT WATER KNOB AT MAXIMUM, TURN OFF TAPS
b)Is the green led
NO
- Replace PCB
permanently on?
YES
c) Is the
Is the
NO
- If the red led is flashing, NTC sensor faulty
red led
NO
red led
off?
permanently
- Insufficient water pressure (below 0,5 bar)
on ?
YES
- Low water pressure switch faulty
YES
d)
Does
NO
Is there continuity on
NO
- Replace PCB
the boiler
DHW flow microswitch ?
- Check, on the PCB, switches 7 and 8 are off
stay
(PCB-M6 connector, across)
off?
terminals 16 and 20 )
YES
- Domestic hot water flow switch faulty
YES
TURN ON THE HOT WATER TAP AT THE MAXIMUM FLOW RATE
e) Does the water
Is the main
NO
- Turn on valves or check the water supply feeding system
come
NO
water supply
through the tap?
turned on?
YES
- Flow rate regulator turned off or boiler inlet filter dirty
YES
f)
- Clean or replace the diaphragm inside domestic water priority valve
- If not continuity on PCB-M6 across terminals 16-20, flow switch faulty
- PCB faulty
- Ignition unit faulty
NO
If the fan is not running:
- Air pressure switch faulty, if there is not continuity across C and NC
- Fan faulty, if there is 230 V across fan connectors
- Ignition unit faulty, if there is not 230 V across fan connectors
Does the boiler
If the fan is running:
start working
Does
- Air pressure switch tubes disconnected or obstructed
and the burner
boiler
- Air pressure switch faulty, if there is not continuity across C and NO
ignite after
NO
Lock-
- Replace PCB if all the above checks did not produce successful result
a few seconds?
out?
If the burner does not
ignite
:
- Insulating gas valves turned off
- Ignition electrode dirty or broken
YES
- Gas valve faulty, if the ignition unit has 230V across terminals 14 - N
during the ignition phase
- Overheat thermostat faulty or boiler temperature over 100°C
- Flue thermostat faulty or in open circuit
- Minimum gas pressure to be adjusted on the gas valve ( see manual )
If the burner ignites:
- Life and neutral reversed polarity
- Ionisation electrode dirty or broken.
- Condensate siphon is not draining or ionization wiring disconnected
- Ignition unit faulty ( no ionization )
YES
