Users Instructions; Fault Finding; Safety Features Summary; Fault Finding Procedures - Hamworthy Purewell Installation, Commisioning And Maintenance Instructions

Combustion figures for Natural Gas should be as
follows: -
CO = 9% (Dry flue gas).
2
CO = 0-50ppm: however figure should not exceed
200ppm under normal operating conditions.
Details of flue gas composition relating to propane firing
can be found in Appendix 'A'.
The flame supervision device can now be checked by
closing the gas cock on the inlet of the gas valve
(Pilotstat models) or by pressing/twisting the stop button
on the gas control valve (Operation dependent on gas
valve type fitted.) for non-Pilotstat models. After
approximately 45 seconds the solenoid valve should
be heard to click closed. Wait a further 3 minutes and
carry out pilot lighting procedure.
11.8 User's Instructions
When the above is complete, the end user or their
representative should be made aware of the lighting
and operating instructions fitted to the inside of the boiler
door. A practical demonstration should be given
describing each functional step. This Installer's Guide
and user's instructions should then be handed over and
be kept in a safe place for easy reference.

12.0 FAULT FINDING

12.1 Safety Features Summary

Should the control thermostat fail, the temperature
limiter will trip thus creating an immediate shutdown
regardless of firing mode. If this occurs the temperature
limiter situated in the controls housing will require re-
setting by pushing the small pin in firmly. Note! Access
to this pin is gained by removing door and unscrewing
safety cover (if fitted). An investigation should be carried
out to ascertain the reason for the overheating. An
obvious reason would be too low a water flow rate
through the boiler. NOTE! The pilot will not remain
established if this pin is not re-set manually.
Volt free contacts are available for connection to BEM
system (optional extra). Non-Pilotstat models require
a pressure switch to be fitted in the pilot gas line and in
the event of pilot failure this activates a lockout relay in
the controls and neon on the fascia.
All propane-firing boilers are fitted with a low gas
pressure switch (set at 20mbar). Should the gas supply
pressure fall below this level, the boiler will not operate.

12.2 Fault Finding Procedures

General fault finding is shown in Figure Nos.18a & 18b.
If the boiler still cannot be operated satisfactorily after
following the chart, consult your local office of
Hamworthy Heating for assistance.
HAMWORTHY HEATING LTD.

12.3 Possible Causes of Boiler Lockout

1) Pilot failure due to faulty thermocouple.
2) Weak pilot due to blockage in pilot orifice.
3) No or low gas supply pressure.
4) Temperature limiter operating due to high boiler
temperature or faulty thermostat.
5) Faulty main gas valve.
6) Loose ECO lead from gas valve to thermostat.
(Non-Pilotstat models)
7) No electrical supply (Pilotstat models)

13.0 SERVICING

13.1 Regular annual servicing is recommended to
ensure trouble free operation. Although cleaning of
flueways may not be necessary on a yearly basis, it is
important that all controls and safety features are
checked for correct operation. NOTE! Measuring flue
gas CO
of the state of the boiler flueways and waterways.
Results should be compared with previously measured
values to establish possible loss of efficiency.
13.2 Before servicing the boiler, the following procedure
must be carried out: - WARNING: Isolate all electrical
supplies and turn off the gas service cock to the
boiler module being serviced.
1) Remove the front casing door using a screwdriver to
rotate the 1/2 turn latch.
2) Turn off gas service cock, (fitted upstream of gas
control valve).
3) Undo both screws on gas valve wiring plug, situated
under controls assembly, and disconnect plug
completely by pulling firmly downwards.
4) Disconnect ECO connectors at gas valve (if fitted),
undo and disconnect pilot bundy tube from gas valve:
disconnect piezo lead and thermocouple.
5) Slacken union below gas service cock and release.
Slacken and remove nuts/washers holding gas valve
and manifold assembly. Remove manifold assembly
taking care not to damage or twist bundy tubing or gas
valve, etc.
6) Undo and remove igniter assembly by removing
screws from front tie bar (2 off). Carefully remove igniter
assembly from under burner bar tie rod taking care not
to twist or bend igniter electrode or bundy tubing. See
Figure No. 10 for position of items. Check condition of
igniter assembly thermocouple and injectors for
damage, clean as required.
7) Carefully remove burner assembly by pulling and
lifting burner front plate.
Check burner bars condition and clean using a soft
brush if required (if possible use compressed air to blow
out the dust inside the bar). Damaged or cracked burner
bars should be replaced. To replace an individual bar
will require drilling out the rivets holding it on to the
front plate. A new single burner bar will be supplied
with clinch nuts and screws to fix onto the front plate.
16
PUREWELL PERMANENT IGNITION
and gas temperatures will give an indication
2
500001045/F