HAMWORTHY HEATING LTD
35
PUREWELL VariHeat he
500001155/F
11.0 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 carry out the appropriate part of the commissioning procedure & check the
operation of each component replaced. See
Section
7.3:Commissioning and Testing
NOTE: Isolate electrical supply to the boiler and turn off the gas supply after removing controls cover
and before commencing any servicing or component exchange procedure.
11.1 Igniter and Flame Probe Assembly
Both Ignitor and flame probe are secured in the same manner.
Reference to Figure 11.1 shows position of igniter assembly. To remove assembly disconnect the plug/socket on
the supply lead and remove the screw securing the igniter to the burner front panel. Figure 11.1 shows diagram of
igniter assembly and relevant components. Renew components as required and generally remove any loose
sooty deposits and clean as required. Ensure positions of components are as recommended in Figure 11.1.
11.2 Safety Temperature Limiter (Limit Stat)
With the boiler front cover removed, the Limit Stat is situated on the rear of the control panel fascia bracket to the
left hand side of the main PCB.
Remove the 'push on' spade connections from the temperature limiter body noting position of coloured cables.
Remove plastic cover (if fitted) and unscrew holding nut to detach temperature limiter from housing. Gently feed
the capillary back through the controls bulkhead. Re-set temperature limiter to 95°C. Check the operation of the
device by carefully applying a heat source to the bulb. Re-assemble temperature limiter into controls housing
ensuring correct cable notation. Refer to Figure 9.0.
11.3 Main Gas Valve.
NOTE!
Hamworthy Heating strongly recommend that a new gas valve assembly is fitted to ensure safe, reliable
operation of the boiler.
The gas valve is supplied as a factory set component & must not be tampered with.
1)
Disconnect the gas valve electrical plug and pressure switch plug.
Remove the four socket head screws securing the gas valve inlet flange. Take the weight of the gas valve and
remove the four socket head screws securing the gas valve to the discharge pipe assembly. Withdraw the gas
valve.
2)
Always fit new ‘O’ rings to both inlet and outlet when replacing the gas valve.
Always test for gas soundness after replacement parts have been fitted.
Refer to
Section 7.1,
if necessary for valve integrity check procedure.
3)
Re-light the boiler using instructions on the inside of the door. Check for correct operation. If necessary, refer
to
Section 7.4 Commissioning the Boiler
, for correct procedures.
11.4 Combustion Fan
NOTE! To remove the fan, it is necessary to remove the gas valve and discharge pipe assembly.
1)
Disconnect the gas valve plug assembly from the gas valve and pressure switch. Disconnect the gas valve inlet
flange from the gas valve. Disconnect the 3 & 5 way electrical plugs from the fan body.
2)
Disconnect the fan/gas valve assembly from the burner body by removing the 4 M8 nuts securing the transition
duct to the burner.
3)
Remove the screws securing the gas valve and discharge tube assembly to the air inlet box and carefully place
to one side (PV65he and PV85he Models only).
4)
Remove the screws securing the air / gas mixing device to the fan and withdraw the air inlet box, carefully
place to one side (PV65he and PV85he Models only).
5)
Remove the screws securing the fan outlet to the burner transition duct. Beware there is a non return valve
fitted between these components.
6)
Re-assemble in reverse order using new gaskets where appropriate. After assembly and prior to re-fitting the
assembly to the burner, check for correct and free operation of the non return valve in the burner transition duct.
