Technical data

Primary Heat Exchanger
Refer to Figs. 14,15 and 33.
Drain the appliance. Lower the facia and remove the inner casing
cover.
Remove the control module, the air flow switch and the plastic
air distributor from the gas valve.
Disconnect and remove the sensors and the flue thermostat from
the bottom left-hand side of the heat exchanger.
Disconnect and remove the hot water flow pipe from the front of
the heat exchanger.
Remove the gas supply pipe to the fan.
Release the clip at the base of the flue duct by unscrewing the
single screw and push the duct upwards to release it from the
elbow at the base of the heat exchanger.
To increase the access remove the pump completely and remove
the pipe connection to the expansion vessel.
Unscrew the hexagon head screw on the outside of the rear
right-hand side of the cabinet and remove the condensate drain
bracket.
Unscrew the plastic nut securing the top of the condensate drain
at the rear of the pump and put the drain assembly to one side
releasing its connection to the condensate collector at the base
of the heat exchanger.
Pull out the condensate collector from the base of the heat
exchanger.
Unscrew the two screws at the top securing the heat exchanger
backing plate to the top of the inner case back panel.
The heat exchanger can now be pulled forward and removed
from the appliance with the fan and burner assembly. Take care,
as some water will remain in the heat exchanger.
Transfer the relevant components to the new heat exchanger and
fit to the appliance in the reverse order.
Important: Fit the circular rubber seal to the base of the heat
exchanger AFTER the heat exchanger has been refitted to the
appliance.
Use new gaskets or seals where any appear damaged.
Ensure that the flue duct is correctly connected.
Refill, vent and re-pressurise the system.
Check for the correct operation of the appliance by following the
Commissioning procedure described in section 13.
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