Glow-worm Ultrapower 100sxi Installation And Servicing page 49

14.18 Safety Discharge Valve
For access, refer to section 14.1.
Refer to section 14.1 and drain the boiler heating circuit.
The safety discharge valve is situated towards the RH side of
the boiler module, refer to diagram 14.14.
Unscrew the pipework union nut from the safety discharge
valve.
Remove the securing clip and withdraw the safety discharge
valve.
Fit new 'O' ring.
14.19 Domestic Water Thermistor
For access, refer to section 14.1.
The domestic hot water thermistor is situated centrally in the
boiler module on the DHW inlet pipe, refer to diagram 14.15.
Disconnect the domestic hot water thermistor electrical
connections
Remove hot water thermistor.
NOTE: When reconnecting electrical connections, polarity is
not important.
Carry out a functional test of the controls.
14.20 Heating Flow Thermistor
For access, refer to section 14.1.
The heating flow thermistor is situated underneath the heat
exchanger, refer to diagram 14.16.
Remove the electrical connections from the thermistor.
Remove the thermistor noting its position on the flow pipe.
NOTE: When reconnecting, the polarity of the wiring to
thermistors is not important.
SAFETY
DISCHARGE
VALVE
14 Replacement of Parts
SECURING
CLIP
UNION
NUT
Diagram 14.14
LOW WATER
PRESSURE
SENSOR
HEAT EXCHANGER
HEATING
FLOW
THERMISTOR
14.21 Heating Return Thermistor
For access, refer to section 14.1.
Refer to diagram 14.17.
Remove the electrical connections from the thermistor.
Remove the thermistor and noting its position on the return
pipe.
NOTE: When reconnecting, the polarity of the wiring to
thermistors is not important.
14.22 Automatic Air Vent
For access, refer to section 14.1.
Refer to section 14.1 and drain the boiler heating circuit.
Refer to diagram 14.18.
Remove the retaining clip to release the automatic air vent.
Fit the new automatic air vent and 'O' ring ensuring the vent
cap is left loose.
DOMESTIC
HOT WATER
THERMISTOR
Diagram 14.15
Diagram 14.16
49