HAMWORTHY HEATING LTD
WESSEX-HE 200 BOILER
500001008/K
16
remove each of the four individual side panels.
b) Undo all the M5 screws retaining opposite
stainless casing side panels and remove by pulling
out at the top and then lifting; if caution is exercised
the silicone rubber seal will come away intact on each
side panel and can be re-used.
c) Unhook both stainless coil spring baffle retainers
and remove. Also remove the 16 stainless steel
baffle plates. Wire brush both sides of the baffles to
remove any deposits.
d) Thoroughly brush the exposed finned copper tubes
until clean. (The tube bank may be gently hosed
down with clean water to remove debris providing the
burner is removed). If compressed air is available,
use to remove debris dry or excess water.
e) De-sludge the floor of the casing and ensure the
drain is clear.
13.3.3
If necessary repair the silicone rubber seal
around edges of side panels with new liquid sealant.,
allow 20 minutes for partial cure, or replace with
silicon rubber strip.
13.3.4
Replace one coil spring baffle retainer around
tube bank and slip in baffles one at a time. When all
the baffles are repositioned replace the second
retainer spring and locate between tabs on baffles,
ensure first retainer is similarly located. Now lightly
smear grease over side sealing faces of casing if
using liquid sealant gasket.
13.3.5
Replace side panels carefully to avoid
damaging repaired seal etc. and tighten screws.
Clean off any excess liquid rubber that may squeeze
out.
13.3.6
Continue with re-assembly in accordance with
procedure for annual service: paragraphs 13.2.7 to
13.2.10.
13.4 Four Year Service
13.4.1
Either the heat exchanger module may be
descaled in situ*:
Repeat two-year services as described in paragraphs
13.3 to 13.3.5 inclusive then:
13.4.2
Isolate the boiler from the main system flow
and return pipes and circulate a chemical descaling
solution through the heat exchanger, preferably using
a pumped recirculating system. This is best carried
out by specialists using suitable chemicals. Follow
the chemical manufacturer’s recommendations and
instructions regarding method, solution strength and
safety and handling precautions.
Reconnect boiler to pipework system after cleaning
up flanges and renewing gaskets.
NOTE:
Fit flange bolts so that nuts are uppermost on
flow connection, and underneath on return
connection. This is important to avoid controls cover
fouling bolts.
Now proceed to paragraphs 13.4.12 and 13.4.13.
* Or alternatively the heat exchanger module may be
removed for descaling:
13.4.3
Carry out annual service as previously
described in paragraphs 13.2.1 to 13.2.6 inclusive, do
not re-assemble any items to boiler.
13.4.4
a) Release 25mm gas union connecting manual shut-
off valve to boiler pipework.
b) Undo the M8 nut and bolt clamping the vertical gas
feed pipe. Undo both M8 set screws retaining gas
controls assembly to water return elbow. Remove
gas control assembly.
13.4.5
a) Isolate the boiler from the main system flow and
return pipes and drain boiler. (It contains
approximately 20 litres).
b) Remove filter tray assembly by slackening the six
(three each side) M5 pan head screws and lift off at
the keyhole slots.
13.4.6
Either:
a) Remove the six M10 nuts holding the heat
exchanger module to the casing, and carefully
withdraw the module from its casing by sliding it out
on its internal runners. The module is heavy (137kg)
and will require frontal support as soon as the front
flange clears the studs. Otherwise tube bank
damage will result. Also support the rear of the
module as it emerges from the casing.
Alternative to a) above if space permits:
b) Disconnect boiler casing from flue duct and
remove water flow and return pipework local to boiler
front including elbows up to front header casting.
Undo four of the six M10 nuts (front header to casing)
leaving the two outer nuts in place (those on
horizontal centre line of module). Tip casing forward
onto front header casting using timber or similar to
protect studs etc. and to shore up.
Undo the remaining two M10 nuts and gently lift
casing from the module.
Return casing to normal position for cleaning.
