Replacement Of Failed Components - Hamworthy WESSEX-HE 200 Installation, Commissioning And Servicing Instructions

14.0 REPLACEMENT OF FAILED COMPONENTS

There are a number of components listed below
which can be replaced simply and quickly by following
the given procedure. In each case carrying out the
appropriate part of the commissioning procedure
must check the operation
component. See section 11.0.
NOTE: ISOLATE ELECTRICAL SUPPLY TO THE
BOILER AND TURN OFF THE GAS SUPPLY
BEFORE REMOVING CONTROLS COVER AND
COMMENCING ANY SERVICING OR COMPONENT
EXCHANGE PROCEDURE.
THAT ONLY GENUINE SPARE COMPONENTS
ARE USED AND ELECTRICAL CONNECTIONS
CORRECTLY MADE.
14.1 Pilot Burner Assembly - HHL Part No.
563801004.
The pilot burner is situated on the horizontal centre
line to the right of the fan extension duct, screwed to
the front header casting.
Pull off the HT and flame probe caps, loosen nuts
securing pilot gas supply pipe and remove; remove
the two M5 screws and withdraw the assembly.
Renew insulated spark and probe electrodes as
required -
HHL Part Nos.
Spark Electrode 333801440
Flame Probe 533805006
Generally clean up pilot assembly removing any
loose sooty deposits or oxidisation and replacing any
damaged parts, see Figure No. 10 (Assembly
Drawing).
Check pilot assembly. If either electrode shows signs
of oxidation or is bent it should be renewed.
Check spark gap is set at 2 to 3mm. Adjust if
necessary. If lack of gas flow is suspected, check the
pilot filter by removing the brass pilot gas supply
fitting screwed into the left hand side of the main gas
inlet manifold. The fitting contains a secured foam
filter pad. Blow through carefully in reverse gas
direction to clear any debris or replace fitting
complete with new filter ensuring joint is gas tight.
Replace pilot assembly in reverse order.
14.2 Fan Motor Renewal
533901295.
First check that the replacement motor assembly has
been supplied with the motor plate and 5-pin Wieland
plug fitted, and that there is a replacement rubber
HAMWORTHY HEATING LTD
of each replaced
ALWAYS ENSURE
- HHL Part No.
18
WESSEX-HE 200 BOILER
gasket packed loose.
Un-plug fan assembly from main controller wiring
loom.
Remove the four M5 'Pozidrive' screws holding the
controls bracket and fan motor plate to the fan casing.
Place the controls bracket to one side taking care not
to stretch or pull any cables or capillaries etc.
Withdraw the fan, also removing the existing rubber
gasket. Slacken the impeller retaining grub screw
and remove the impeller from the motor shaft.
Select the new motor that is supplied complete with
new motor mounting plate and check plate is secure
and rubber grommet is in position between motor and
plate around the shaft.
Position the impeller on shaft to give a 6mm gap
between motor plate and impeller back plate at the
rim of the latter. Tighten the retaining grub screw
onto the flat surface provided on the motor shaft.
Rebuild the assembly in reverse order to remainder of
removal procedure, using the wiring diagram on the
controls cover to assist with wiring connections to the
plug, if required. NOTE! A 5-pin plug and socket
arrangement is used.
supplied with replacement motor.
Always replace the fan casing rubber gasket with the
new one supplied with the replacement fan motor.
14.3 Pilot Solenoid Valve Renewal (Coil only) - HHL
Part No. 533903031
It is likely that the main cause of gas valve failure will
be due to coil winding failure either open or short
circuit. In such an event it is possible to replace the
coil only.
Disconnect the Din Plug from the valve coil by
loosening the securing screw.
Unscrew the nut on top of the valve and lift coil from
valve stem. Replace with new coil in correct
orientation. Refit and tighten the top nut and Din Plug.
14.4 Main Solenoid Valves (Natural Gas Only)
NOTE: - If one of the main solenoid valves is to be
replaced, the correct model for the gas being fired
MUST be fitted.
NOTE: -For Propane firing refer to Appendix 'A'.
Main gas valve HHL Part No. 533903021
By-pass gas valve HHL Part No.533903025
NOTE! Only gas valves with an identical Type No.
may be used for replacement purposes. Please
For wiring, see diagram
500001008/K