12.0
Servicing the Boiler
37
© Baxi Heating UK Limited 2005
12.1
Annual Servicing (Cont)
NOTE: The information shown on the display is
explained on the label on the inside of the lower
door panel (see Fig. 38).
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 (100 & 80 HE Plus models)
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 (Fig. 44).
NOTE: The 133 HE Plus burner skin is fragile -
handle with care. Clean and if necessary replace the
burner (Fig. 44).
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 panels and check condition
(Fig. 44). Replace the insulation pads if necessary.
k) Ensure the heat exchanger fins are clear of any
obstruction, use a thin bladed tool to remove debris. The
use of a torch at the heat exchanger top and a mirror
held under the heat exchanger will aid observation of the
heat exchanger fins.
l) Check condition of all seals.
Important: Pay particular
attention to the condition of the combustion box door
seals.
m) Reassemble in reverse order, applying a suitable silicon
based grease to “O” rings and seals - Greasil 4000
(Approved Silicone Grease).
12. Check CO/CO
2
ratio at flue sampling point (Fig. 41a).
See section 4.0.
13. 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.
Fig. 42
Burner
Fig. 43
Electrical Supply
Fig. 44
Wing Nuts
Protection
Sensor
Leads
Fan
Injector Pipe
Securing Nut
Condensate
Trap
Sensor
Leads
Locking Nut
Condensate
Drain Pipe
Central Insulation
Panel
Burner
Combustion
Box Base
Heat Exchanger
Support Bracket
Combustion Box Base
Securing Screws
Burner Securing
Screws
Venturi
Injector Pipe Retaining
Screw (100 & 80 HE
models)
100 & 80 HE
Burner
Fig. 41a
Flue Sampling Point
