Burner & Combustion Chamber - andrews NEOflo SC25/200 Installation, Operation And Maintenance Manual

SERVICING
Health and Safety Statement :
Th is Heater contains no asbestos.
In all cases, before work commences turn off the Mains
Electricity and Gas Supply.
Routine Service
To ensure continued effi cient operation of the Heater
it is recommended that it is checked and serviced at
regular intervals.
Th e frequency of servicing will depend upon the particu-
lar installation and usage but in general every twelve
months should be the maximum.
It is law that any service work should be carried out by
Registered personnel.
1. Clean the burner and check the combustion chamber.
2. Check condition of ignition spark and sensing probe.
3. Check the air duct and fl ue seals.
4. Check condensate syphon and pipework for leaks.
5. Check the combustion CO, CO
Follow the procedures given in Changing Components for
parts removal in addition to the following notes.
In all cases, before work commences turn off the mains
electricity and gas supply
Burner & Combustion Chamber
To clean the burner and view the inside of the Combus-
tion Chamber it is necessary to remove the Fan and Gas
Valve:
• Remove lower front panel.
• Disconnect the gas cock fl ange from gas valve.
• Unplug fan electrical connector.
• Remove air tube from venturi.
• Undo the cover over ignition control connec-
tions and remove the three connectors.
• Pull off the ignition and earth lead connec-
tion on the valve and heat exchanger.
• Undo the two screws holding the venturi and gas
valve to the fan and remove.
• Undo the four screws holding the fan mounting
spacer to the sump and remove.
• Inspect the rubber burner gasket fi tted between
the burner and the fan mounting spacer and
replace if damaged.
• Th e burner should withdraw with the spacer and
expose the inside of the combustion chamber. Note:
Th e burner is marked with a line which should be
used to position it. It should align with fi xing hole
for the spacer to the left of the electrode assembly.
• Assembly is the reverse.
NEOfl o Water Heater
and Gas Rate.
2
23
Spark & Sense Electrode
• Turn off the Heater.
• Pull off the HT and Earth leads.
• Remove the cover over the Ignition Control
connections and pull it off the Gas Valve.
• Undo the two screws retaining the electrode
assembly and carefully withdraw.Th e spark gap should
be 3.0 mm ± 0.5.
• Assembly is the reverse, ensuring the gasket
correctly placed.
Air Duct & Flue Seals
A visual inspection should establish there are no leaks
around any of the seals, including the fl exible Air Duct to
the Venturi.
Condensate Syphon
Th e lower bowl of the Syphon can be unscrewed, examined
and cleaned. Check its connection to the Heat Exchanger
and pipework for leaks.
Gas Rate & Combustion
See the Datatable on the inside of the cover for the cor-
rect values.
A Combustion sample point is provided at the front of the
Sump. (Fig.9.4)
To check, re-establish gas and electricity and then run the
Heater for at least 5 minutes. If adjustment is required
remove the cover over the Th rottle screw and turn anti-
clockwise to increase CO , clockwise to decrease.(Fig. 9.1)
2
Allow at least a minute between adjustments to obtain
stable readings.Th e Gas Rate will be correct when the CO
and CO fi gures are to specifi cation.
2
CHANGING COMPONENTS
NONE OF THE CONTROLS ARE REPAIRABLE IF THEY ARE
NOT WORKING THEY MUST BE REPLACED.
In all cases, before work commences turn off the Mains
Electricity and Gas Supply.
Th e following items can be replaced:
Pressure Temperature Relief Valve
Th e LCD Display. .
High Limit Sensor.
Tank Sensor.
Flue Th ermostat
Ignition Control.
Electrode
Gas Valve.
Fan.
is
September 2015