Electrolux Nano Pro User manual

SERVICE MANUAL
PILOTLESS ELECTRONIC WATER HEATERS
1.- NO IGNITION No spark present. ...................................................................... 2
2.- NO IGNITION Water Heater sparking but the burner does not ignite. ............................ 3
3.- THE WATER FLOW IS VERY LOW ...................................................................... 3
4. CONTINUOUS SPARKING WHEN WATER HEATER IS IGNITED ...................................... 4
5.- SPARKING, BURNER IGNITES FOR A FEW SECONDS AND THEN SWITCHES OFF............... 4
6.- HARD IGNITION OF THE WATER HEATER THERE IS NO SOFT START.......................... 5
7.- WATER HEATER CONTINUES SPARKING WHEN TAP IS TURNED OFF............................. 5
8.- WATER HEATER SWITCHES OFF AFTER FEW MINUTES OF OPERATION ........................ 6
9.- WATER HEATER REMAINS IGNITED WHEN TAP IS CLOSED ...................................... 7
10.- FLAMES IN BURNER ARE YELLOW ..................................................................... 7
11.- THE BATTERY LIFE IS VERY SHORT .................................................................. 8
12.- USEFUL DATA............................................................................................. 9
13.- IGNITION SEQUENCE ..................................................................................10
14.- PHOTO GALLERY .........................................................................................11

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1.- NO IGNITION No spark present.
SYMPTOM POSSIBLE CAUSE OF FAILURE SOLUTION
No Spark
Check there is a battery in the Battery Box Insert a full battery in the Battery Box. Photo 1
Check that the battery is placed in the Battery Box in the correct
position Correct the position of the Battery. Photo 1.
The switch in the electronic circuit is in off position. Turn the switch on (inner position). Photo 4
The micro switch is not correctly connected or the connectors are
loosened. Check the status of the micro switch connection. Photo 7
Low water pressure. The main gas valve is not opening.
Check the water pressure.
Change the position of the temperature selector to Max.
temperature. ( Min Water Flow) Photo 4
The water inlet filter is dirty. The Water Flow is very low. Clean the water filter. Photo 3
The micro switch is not working correctly.
Disconnect the micro switch from the circuit. Shut off the gas inlet.
Short circuit the terminals in the electronic circuit. The circuit must
generate spark if circuit is O.K.
Adjust / Change the micro switch. In case it is necessary.
High ambient humidity. No sparking between electrodes. Dry the electrodes and clean them. Photo 5
The spark electrode wires have lost their insulation. Sparking is
taking place between the wires and earth or between the two
wires.
The electrode connector is defective.
Replace the electrode unit. Photo 5
The Ground connection of the electronic circuit is not correctly
connected. --> The Servo hasn’t any Voltage. Tighten the ground connection terminal. Photo 6
Wires not well connected to electronic circuit. Check the wiring installation.
TTB switch in Draught diverter is tripped Check that TTB is not Tripped (Tripped means contact opened).
Water valve diaphragm broken.
Communication channel between chambers obstructed.
Disassemble Water Valve. Change the diaphragm.
Clean the communication channel. Photo 8.
All models
Venturi obstructed. Check and change venturi. Photo 9.

3 of 15
SYMPTOM POSSIBLE CAUSE OF FAILURE SOLUTION
No Spark
Water valve O-rings are blocked. Disassemble Water Valve. Work the water pin manually to unblock
them / Change the top cover of the water valve. Photo 10.
All models
Main gas valve seal is blocked. Work the gas pin manually to unblock the O-ring. Photo 11.
Change Gas valve.
2.- NO IGNITION Water Heater sparking but the burner does not ignite.
SYMPTOM POSSIBLE CAUSE OF FAILURE SOLUTION
Battery Voltage very low. Sparkling is very at low frequency and
sounds very weak. Replace Battery. Use Alkaline battery. Photo 1
Battery is not correctly inserted in the Battery box. Check position of the Battery. Photo 1
No gas.
Low gas pressure. Open gas valve. / Check gas pressure.
Main Gas Valve is not opened. Microswitch needs adjustment Adjust Microswitch. Must be activated only with main valve opened
The spark is not generated in the sparking electrode. Check humidity on electrodes. Photo 5.
Check position of electrodes or whether they are deformed.
There is no voltage in Servo valve terminal.
Check the Electronic circuit earth connection. Photo 6.
Check the wiring.
Change the Electronic circuit.
It sparks but
the burner does
not ignite
In case there is voltage in servo terminal. Change the gas valve. The servo is incorporated in the gas valve.
3.- THE WATER FLOW IS VERY LOW
SYMPTOM POSSIBLE CAUSE OF FAILURE SOLUTION
Water pressure is too low. Change the position of the water selector to MAX.. Photo 4
The water filter is dirty. Clean the water filter. Change the water filter. Photo 3.
The water flow is
very SMALL and the
water is coming out
VERY HOT. The heat exchanger in combustion chamber is obstructed. Clean the heat exchanger.
Change the combustion chamber.

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4. CONTINUOUS SPARKING WHEN WATER HEATER IS IGNITED
SYMPTOM POSSIBLE CAUSE OF FAILURE SOLUTION
Continuous sparking
and burner is ignited
The electronic circuit is not working correctly. Replace the Electronic circuit. Photo 2.
5.- SPARKING, BURNER IGNITES FOR A FEW SECONDS AND THEN SWITCHES OFF
SYMPTOM POSSIBLE CAUSE OF FAILURE SOLUTION
Air in gas pipes. Purge air from gas pipes.
Low gas pressure. Check gas pressure.
The electrode unit has come loose.
The electrode flame sensor is out of position.
The electrode flame sensor is deformed. See manual:
electrodes life….
The electrode connector is not properly connected.
Tighten the electrode fixing screw. Photo 5.
Change the electrodes.
Check the connection of this connector. Photo 7 & Photo 13.
The electronic circuit Ground terminal is not properly
connected. Tighten the Ground connection terminal. Photo 6.
Electronic circuit is defective. No Voltage in Servo terminal Change the electronic circuit.
The burner switches
off after remaining
on for a few
seconds
Servo Valve is defective Check Voltage in Servo terminal. Photo 17.

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6.- HARD IGNITION OF THE WATER HEATER THERE IS NO SOFT START
SYMPTOM POSSIBLE CAUSE OF FAILURE SOLUTION
Battery Voltage very low. Sparkling is very at low
frequency and sounds very weak. Replace Battery. Use Alkaline battery. Photo 1.
The electrodes are not correctly fixed to the manifold.
They are too high referred to the burner blades. Fix the electrodes correctly using the fixing screw. Photo 5.
There is a gas accumulation in the combustion chamber Electronic circuit defective, there is servo voltage with no Flame.
Check Servo valve closes when no energized.
There is air in the gas supply line. Drain the gas circuit.
Excessive gas pressure. Check the gas inlet pressure Photo 17. Nominal gas Pressure 13 mbar.
Check / adjust the gas pressure in the burner Photo 12.
The Ground terminal of the electronic circuit is not
properly connected. Tighten the Ground connection terminal. Photo 6.
Defective wiring of electronic circuit. Check the wiring and change it if necessary.
The servo is not working correctly. No soft start function Change the gas valve. The Servo is integrated in the gas valve. Photo 17.
The burner ignites
WITHOUT SOFT
START
The nozzles are not well fitted. The change of gas type has not been made correctly.
7.- WATER HEATER CONTINUES SPARKING WHEN TAP IS TURNED OFF
SYMPTOM POSSIBLE CAUSE OF FAILURE SOLUTION
Micro switch not properly adjusted. Check micro switch adjustment. Microswitch adjustment screw Photo 17.
The micro switch has broken (The contacts are stuck).
Sparkling only occurs for 5 seconds. Check function of micro switch Change the micro switch Photo 17 –
The water heater is
sparking when the
tap is turned off.
The Electronic circuit is faulty. Change the Electronic circuit Photo 2.