76
Figure 11-8: Top of heat exchangers
11.6.2 Heat exchangers
Shut off the cold water supply to the
wash system.
To gain access to the top of both heat
exchangers. (Refer to Figure 11-8):
• Remove the boiler top casing
panel.
• Unscrew and remove the two
nuts (and washers) securing the
front access panel and remove it
from the top of the primary heat
exchanger.
• Unscrew and remove the two nuts
(and washers) securing the rear
access cover and remove it from
top of the secondary (condensing)
heat exchanger.
Primary heat exchanger – clean as
follows:
• Remove all of the mild steel spiral
baffles by lifting them vertically
up and out from the primary heat
exchanger tubes.
• Clean down any ash inside tubes,
using a suitable pipe brush, into
the combustion chamber and ash
pan below.
• Clean all ash deposits from top
chamber of the primary heat
exchanger (above tubes) and
shaker mechanism/plates, using
brush and vacuum.
• Clean and check condition of all
spiral baffles.
• Re-fit spiral baffles into heat
exchanger tubes, fitting them
through shaker plates.
• Lift and drop each spiral to check
that all spirals are free to move in
their respective tubes.
Secondary heat exchanger – clean
as follows:
• Disconnect the flexible hose from
the wash system manifold.
• Check and clean (if required) the
two wash system jets.
• Remove all of the stainless steel
Spiral baffles from the secondary
heat exchanger tubes.
• Clean all ash deposits from top
chamber of secondary heat
exchanger (above tubes) and
from rear flue gas duct (at rear of
secondary heat exchanger) using
brush and vacuum.
• Clean down any ash inside tubes,
using a suitable pipe brush, into
the base of the condensing heat
exchanger below.
• Ensure that ALL ash deposits are
removed from base of rear flue gas
duct.
• Clean and check condition of all
spiral baffles. Replace if necessary.
• Re-fit spiral baffles into heat
exchanger tubes, such that all
the top edges of the baffles are
running ‘front to back’. Refer to
Figure 11-9.
• Check the two wash system spray
jets on the underside of the rear
access panel are not blocked.
• Inspect the condition of the REAR
access panel before re-fitting.
Replace any damaged or worn
rope seals if necessary
• Re-fit REAR access panel and
secure with the nuts (and washers)
previously removed. Do not
overtighten.
• Ensure that the rear access panel
is fitted with the flue gas sample
point in the rear left-hand corner.
• Reconnect the flexible hose.
• Turn on the cold water supply to
the wash system.
Figure 11-9: Spiral baffles
• Check the operation of the
automatic cleaning of the heat
exchanger. Refer to Section 10.3.3.
11.6.3 Combustion Chamber
Disconnect the pellet delivery hose from
the burner pellet feed tube. Fully open
the combustion chamber door on the
front of the boiler and clean as follows:
• Clean the underside of upper
rear section of the primary
heat exchanger (at the rear of
combustion chamber).
• Remove the ash pan and dispose
of the ash in a safe manner.
• Clean down the combustion
chamber side, back and base
surfaces, removing all ash
deposits.
• Clean any ash deposits from
the top of the burner hood and
the inner face of the combustion
chamber door.
• Clean out the burner brazier to
remove as much loose ash as
possible using a vacuum.
• Refit the ash pan in the base of the
combustion chamber.
• Grease the front cleaning door
latch mechanism and close the
door.
!
WARNING
Ensure ash has cooled before
removing ash pan. Extreme care
is required when emptying the ash
pan as smouldering ash could be
present and cause serious damage
to persons or property.
!
WARNING
Ensure the electrical supply to the
hopper and boiler is isolated before
proceeding.
To Next Page
Loading...
