Hamworthy Sherborne Series Installation, Commissioning And Servicing Instructions page 33

10.2.2.2 SE71c
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Isolate the boiler from the system & drain it down.
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Disengage the appliance flue connector from the sump casting. Un-plug the condensate tube from the trap
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On the SE71c Model remove the return (lower) connection & heat exchanger connecting pipe from the rear of
the boiler, secured by M8 nuts & washers. Note, there is an 'O' ring used on each fitting.
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Support the sump & remove the 4xM6 securing nuts. Lower the sump to expose the heat exchanger & baffles.
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To clean the heat exchanger(s), the use of a high pressure water hose (40-80 psi) is recommended with the
resultant discharge being collected in a suitable receptacle.
Primary Exchanger - Insert cleaning nozzle into the burner opening. Switch on the pump & traverse the full
length & circumference of the heat exchanger to remove any deposits
Condensing Heat Exchanger - Using the high pressure hose, traverse the exposed top & side of the heat
exchanger angling the sump to drain.
Should a high pressure hose not be available, the respective heat exchangers will have to be removed from the
casings. Each module holds approximately 4 - 5 litres of water & weighs 50 - 60kg (depending on model). It is
strongly recommended that a minimum of two people are on hand to lift the module from the wall. Alternatively,
two lifting eyes are provided for use with suitable lifting equipment.
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Place the module on two blocks of wood so the heat exchanger front casting is supported off the floor to
protect from damage.
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Remove the 4xM10 nuts securing the front casting to the aluminium casing & carefully lift the casing vertically
upwards away from the heat exchanger.
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Unhook the stainless steel springs & remove the 16 stainless steel baffle plates to expose the finned tubes.
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Wire brush both sides of the baffles to remove any deposits.
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Thoroughly wire brush the finned tubes.
10.2.3 Re-assembly
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Re-assemble in reverse order & refit heat exchanger to the casing using a new gasket. Replace the water
connection gaskets on the rear of the boiler. Re-connect the water connections using new 'O' rings. Carefully
lift the module back onto the wall plate & secure with the M10 nut & bolt on the left hand side mounting. Re-fit
the system pipework & check for soundness.
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Re-assemble the fan/transition/burner assembly using new gaskets where necessary, & refit in reverse
order. Test all gas joints broken or disturbed for soundness before firing. Re-light the boiler, check &
adjust the combustion as described in Section 7.
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Check thermostat settings & adjust if required.
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Re-fit the boiler cover & tidy floor around boiler as necessary.
HAMWORTHY HEATING LTD
31
SHERBORNE 500001167/E