andrews NEOflo SC25/200, Installation, Operation And Maintenance Manual

Page: 23 / 32

NEO fl o Water Heater 21 September 2015
1 No Flame established.
2 False Flame detected
3 Overheat sensor > 95C or short circuit.
5 Incorrect Fan speed detected
7 Flue Thermostat tripped
8 Flame circuit error
9 Gas Valve not detected
13 Reset used more than 5 times in 15 mins
21 Control Internal error.
23 Overheat Sensor mismatch
25 Control/Display software mismatch
31 Overheat Sensor1 open circuit.
32 Control Sensor short or open circuit.
33 Overheat Sensor2 open circuit.
34 Low Mains Voltage detected.
99 Communication error between controls.
Burner Lockouts
If the Heater is unable to light or detects a safety condi-
tion the control will lockout and the Heater will stop
fi r-
ing. Th e display will show RESET and a number referring
to the type of error. See the table above.
To clear a Lockout press the RESET button and provided
the condition has been corrected the Heater will try to
light.
Th ere is a second reset button and indicator on
the Burner Control behind the lower front panel.
Th e Lockout condition should not be repeatedly reset. If
the condition persists then a quali fi ed repair engineer
should be called.
Handover
When commissioning is satisfactorily completed the
operation of the heater and its controls should be
explained to the user and the installation details should
be completed in the back of these Instructions and on
the appliance label.
Finally these instructions should be handed over to the
user.
WARNING : Before commencing or completing any elec-
trical work on the appliance, it is recommended that the
basic safety checks for earth continuity, short circuit,
polarity and resistance to earth are made. All work car-
ried out should follow guidelines laid down by the I.E.E.
OPERATION
Th e Heater requires Mains on both the Live (L) and
Remote Enable connection to be able to run. It is
delivered with a link between them which can be
removed if a Timer or Remote Switch is used.
To run the Heater you must have a Mains supply, Gas,
the Flue
Th ermostat closed and a Tank temperature
below the setpoint.
If all the above are correct then the Gas Ignition Control
starts the Ignition sequence:
1. Th e Fan runs as a pre-purge of the Heat Exchanger.
2. After a few seconds a spark is created at the
electrode and the burner is lit.
3. Th e burner fl ame is sensed and the spark is
removed.
4. Th e Fan speed is then raised to maximum.
5. If it fails to light the burner the spark will stop
and the Fan will run on as a postpurge of the Heat
Exchanger.
6. Th e ignition sequence will be repeated up to fi ve
times, then the control will lockout and will require
a reset to start again.
In all cases, before work commences turn off the Mains
Electricity and Gas Supply.
FAULT FINDING
Table 1.0
CONTROLS AND LOCKOUTS (Table 1.0)
Th e Display indicates the actual and set temperature
of the tank and also displays all the lockouts.
Frost Protection
Th e Heater is fi tted with automatic Frost Protection.
Provided there is Mains and Gas, if the High Limit sen-
sor reads less than 6°C the De-Strati
fi cation pump, if
fi tted, will run and the burner will fi re at ignition rate
until the sensor reads 16°C.
Anti-Legionella
Th e Heater is provided with an automatic Anti-Le-
gionella programme. It set by default to be off but can
be set using in the In Mode (
See Page 22 ). Th is
mode allows the temperature and frequency to be set
between 72 and 168 hours.