14.0 Servicing the Boiler
44
© Baxi Heating UK Ltd 2014
14.2
Annual Servicing - Inspection (Cont)
11. To clean the heat exchanger and burner proceed as
follows:
a) Disconnect the electrical leads to the fan component
protection sensor (Fig. 42).
b) Loosen the screw retaining the gas injector pipe at
the venturi (Fig. 42).
c) Undo the two wing nuts to disconnect the fan
(Fig. 42).
d) Remove the fan and disconnect the electrical supply
to it (Fig. 42).
e) Remove the gas injector pipe from the gas valve
(push-fit) (Fig. 42).
f) Undo the condensate trap securing nut, lock nut and
the condensate drain pipe. Remove the condensate trap
and disconnect the sensor leads (Fig. 43).
g) Remove the two screws securing the burner and
remove the burner. Visually inspect the internal burner
baffle for obstruction, check seal around baffle for
cracks/damage. Clean with a soft brush.
h) Loosen the two screws retaining the heat exchanger
support bracket and slide to the left to remove
(Fig. 44).
i) Remove the four screws securing the heat
exchanger/combustion box base and withdraw the
base.
j) Lower the central insulation panel and check
condition (Fig. 44). Replace the lower insulation pad if
necessary.
k) Ensure the heat exchanger fins are clear of any
obstruction.
l) Check condition of all seals.
Important: Pay particular
attention to the condition of the combustion box
door seals.
m) Reassemble in reverse order and check for leaks.
12. Check the CO/CO
2
ratio and CO
2
level at the flue
sampling point (Fig.41a) is as quoted in Section 4.0,
‘Technical Data’.
13. If the ratio or level is greater than that quoted
telephone the Technical Enquiries for further advice.
IMPORTANT: No adjustment of the gas
valve is permissible.
14. Complete the relevant Service Interval Record
section of the Benchmark Commissioning Checklist at
the rear of this publication and then hand it back to the
user.
Combustion Box Base
Securing Screws
Burner Securing
Screws
Combustion
Box Base
Burner
Wing Nuts
Electrical Supply
Lock Nut
Condensate
Trap
Condensate
Drain Pipe
Securing Nut
Central Insulation Panel
Heat Exchanger
Support Bracket
Injector Pipe
Injector Pipe Retaining
Screw
Protection
Sensor Leads
Fan
Fig. 42
Fig. 44
Fig. 43
Sensor
Leads
Flue Sampling Point
Fig. 41a
Service Drain
Plug
