HAMWORTHY HEATING LTD. PUREWELL AUTOMATIC IGNITION 500001035/G
18
Run the boiler and turn the thermostat up and down
to check for correct operation. Set thermostat to
previously noted setting.
14.3 Temperature Limiter (Limit Stat) Renewal Part
No. 339011044 or 533901179
The temperature limiter renewal procedure follows that
of the control thermostat with some minor differences.
These are as below: -
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 100
°
C. Re-
assemble temperature limiter into controls housing
ensuring correct cable notation. Refer to the
thermostat diagram if terminal identification differs from
those given in Figure Nos. 13 & 13a, (Boiler schematic
wiring diagrams).
14.4 Main Gas Valve.
NOTE!
Some gas valve components can be replaced
without completely removing the whole assembly from
the boiler. However, Hamworthy Heating strongly
recommend that a new gas valve assembly is fitted
to ensure safe, reliable operation of the boiler. Please
refer to Hamworthy Heating Technical Department
before attempting to remove components from the gas
valve.
NOTE!
Only gas valves with an identical Type
No. may be used for replacement. Please contact
Hamworthy Heating spares Dept. for further
information.
Various types and manufacturers of gas valves are
used. Refer to Figure No. 15 for particular valve(s)
fitted.
1)
Ensure power and gas supplies are isolated.
2)
Remove the gas valve wiring plug from the socket
in the controls housing by un-doing both screws and
pulling firmly downwards. Undo the union connection
and 8mm nuts holding the gas valve/manifold
assembly to front plate, this will allow the whole
assembly to be removed from the boiler.
3)
Remove the gas valve by unscrewing cap head
screws holding valve to pipework.
NOTE!
The position
of the relevant electrical cables should be noted,
especially on the 95-120kW boilers. When replacing
the gas valve, it is advisable to renew the ‘O‘ ring seals
sealing both ends. See
SECTION 15.0
Recommended Spares
for Part Nos. Note that the
‘O‘ ring fitted to the 40-80kW (Natural Gas) and all
propane models, is different to that used on the 95-
120kW (Natural Gas) models. Do not over tighten
cap head screws in gas valve body. Ensure electrical
plugs are firmly and correctly located and holding
screws are tightened.
4)
Replace assembly ensuring correct orientation of
the gas valve. Ensure that the gas flow is in the same
direction as the arrow on the bottom of the valve. Refit
all external components and replace plug into controls
housing socket, re-fit and tighten screws holding plug
to housing. Switch on gas and power supply and
check for integrity of all joints using a proprietary leak
detector.
Ensure gas valve(s) operation is correct and safe
before continuing. Refer to Figure No. 3 if necessary
for valve integrity check procedure.
5)
Re-light the boiler using instructions on the inside
of the door. Check and adjust, the low fire/start gas
and high fire gas pressures, refer to Figure No. 1 for
Natural Gas or Appendix ‘A’ - propane firing, for correct
settings. Re-set throttle valve position, if replaced,
see Figure No. 16 for procedure.
If necessary, refer to
Section 11.4 Commissioning
the Boiler
, for correct procedures.
