15 replacement of parts, 19 domestic hot water thermistor, 20 automatic air vent – Glow-worm Ultracom cx User Manual
Page 60: 21 low water pressure sensor
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15 Replacement of Parts
15.19 Domestic Hot Water Thermistor
For access, refer to section 15.1.
Refer to diagram 15.14.
Disconnect the domestic hot water thermistor electrical 
connections
Remove hot water thermistor and retaining clip.
Remove domestic hot water thermistor from clip.
NOTE: When reconnecting electrical connections, polarity is 
not important. 
Carry out a functional test of the controls.
15.20 Automatic Air Vent
For access, refer to section 15.1.
Drain the boiler heating circuit as described in the appropriate 
section of 15.1.
Refer to diagram 15.15 and gain access through the plastic 
maintenance cover.
Unscrew the automatic air vent.
Fit the new automatic air vent and ‘O’ ring ensuring the vent 
cap is left loose. 
Refill, vent and pressurise the boiler.
15.21 Low Water Pressure Sensor
For access, refer to section 15.1.
Drain the boiler heating circuit as described in the appropriate 
section of 15.1.
Refer to diagram 15.16.
Disconnect the electrical lead.
Remove the retaining clip, remove the low water pressure 
sensor.
Fit new ‘O’ ring.
Fit the new low water pressure sensor. 
Refill vent and pressurise the boiler.
13258
Diagram 15.15
AUTOMATIC
AIR VENT
RETAINING
CLIP
MAINTENANCE
COVER
13315
Diagram 15.14
13550
Diagram 15.16