Vaillant ECOmax VUW 236 EH Instructions For Installation And Servicing page 36

6.2.3 Inspect burner
Remove 5 combustion chamber re-
taining screws (3, fig. 51). Slacken 2
side panel spring retaining screws
(2, fig. 51) and remove screw
(4, fig. 51). Remove combustion
chamber front cover.
Unplug the 2 electrical connections
(1, fig. 52) from combustion fan.
Remove the 2 burner retaining clips
(6, fig. 52) by lifting top of clip off of
burner mounting plate.
The burner mounting plate (5, fig. 52)
and combustion fan (4, fig. 52)
assembly can now be removed by lif-
ting the front of the burner mounting
plate up, and pulling forward.
The ceramic burner (2, fig. 53) can
now be visually inspected.
(It is not necessary to clean the burner).
6.2.4 Inspect main heat
exchanger
With the burner / fan assembly re-
moved it is now possible to inspect the
main heat exchanger. Remove any
loose deposits from the heat exchan-
ger, using a brush and jet of water.
(Ensure water is kept away from all
eletrical components.) Remove the
lower part of the condensate trap (1,
fig. 54) by unscrewing. Empty and
clean (ensuring that any debris that
has fallen while cleaning the main
heat exchanger is removed) and fill
with water to about 10 mm from the
top. Refit in boiler.
Reassemble burner and combustion
fan in reverse order.
6.2.5 Check central heating
expansion vessel
NOTE: It is not necessary to perform
this check every year - a check every
three years is sufficient.
Close the boiler CH service valves
(2, fig. 48). Release the pressure from
the boiler as described in Section
7.1.2.
Remove valve cap from expansion
vessel charge point (2, fig. 55).
Check that the internal charge pres-
sure of the expansion vessel is
between 0.7 and 0.9 Bar. If the pres-
sure is lower than this the vessel
should be repressurised using an air
pump. Refit valve cap.
36
fig. 49
fig. 50
fig. 51