Worcester ZWBR 7-28 HE plus Installation And Servicing Instructions page 39

y Loosen any deposits in the heat exchanger from top
to bottom using the cleaning blade. Refer to fig. 46.
Fig. 46
y Clean the heat exchanger from top to bottom using
the brush. Refer to fig. 47.
Fig. 47
y Flush the heat exchanger from the top. Refer to
fig. 48.
y Clean out the condensate collector and trap connec-
tion (with other end of brush).
Fig. 48
y Refit the clean-out cover using a new seal and
tighten screws to torque of approx. 5 Nm.
6 720 610 597 GB (01.07)
Burner
y Check that the gas cock is turned off and the master
switch is in the OFF position.
y Remove the clips (1) and unscrew the two bolts (2).
Refer to fig. 49.
y Unscrew and remove the two hexagon screws secur-
ing the fan (3).
y Slacken fully the rear securing bolt (4).
y Remove the burner coverplate.
Fig. 49
y Remove the burner skin and clean components. Do
not use a wire brush. Refer to fig. 50.
Fig. 50
y Re-assemble burner in reverse order using a new
seal.
y Adjust gas/air ratio (see page 34). Refer to
section 8.2.
Maintenance
39