Technical information

Installation and servicing instructions strictly reserved
for qualified gas installers
39
11.4. Combustion Chamber and Heat
Exchanger.
Refer to diagram 13.3.
Remove loose debris from combustion chamber
using a soft brush and vacuum cleaner. Carefully
flush by spraying water any remaining debris
through the condensate trap (Ensure the water is
kept away from electrical components).
11.5 Condensate Drain
The condense drain does not normally need
removing during servicing.
To flush the condense drain carefully pour water
into the heat exchanger and check that water
flows freely to drain.
If the condense drain is blocked refer to section
13.16 for removal.
GAS VALVE
Diagram 11.4
FAN
COMBUSTION
CHAMBER FRONT
SECURING NUTS
(5 OFF)
IGNITER UNIT
HEAT EXCHANGER
GAS VALVE
ELECTRICAL PLUG
IGNITION LEAD
ELECTRICAL LEAD
GAS PIPE
BRACKET
CHASSIS FRONT
RETAINING SLOTS
ELECTRODE
CONNECTOR
12599
EARTH SPADE
CONNECTOR
11.6 Combustion Check
Once the appliance has been reassembled (apart
from the front and inner casing panels) connect
a CO2 combustion analyser to the test point
on the flue elbow or vertical flue adapter, see
diagram 11.6.
Turn on the gas service cock, see diagram 11.2.
With the power off and the appliance cold, unclip
the controls fascia and hinge it down to reveal the
potentiometers on the rear of the User interface,
see diagram 11.7. Take care not to allow the fascia
to drop down and damage the wiring.
Turn on the electrical supply.
Ensure external controls are calling for heat. The
boiler should fire automatically. Allow the boiler
to fire for a minimum of 60 seconds and then,
using an electrical screwdriver, rotate the ‘service’
potentiometer fully clockwise, see diagram 11.7.