Draining The Boiler - IDEAL Systemiser SE Installation And Servicing Manual

73 DRAINING THE BOILER

IMPORTANT In order to replace the components in
Frames 74 to 82 it is necessary to drain the boiler.
74 CH THERMISTOR SENSOR REPLACEMENT
48
SERVICING
1. Refer to Frame 61.
2. Close the CH isolating valves.
3. Open the boiler drain tap and
drain the water into a suitable
receptacle.
4. To refill the boiler refer to
Frames 5, 37 and 38.
Note. There are 2 control
thermistors - one on the boiler flow
boss and one on the return boss.
1. Refer to Frame 61.
2. Remove the boiler casing. Refer to
Frame 54.
3. Drain the boiler - refer to Frame 73.
4. Disconnect the flexible hose from the
expansion vessel. Release the
expansion vessel retaining bracket
allowing the expansion vessel to be
removed, giving access to the
thermistor sensors.
5. Pull the electrical lead off the sensor.
6. Unscrew the sensor from the boss.
7. Fit the new sensor, using a suitable
jointing compound, and re-assemble
in reverse order.
Systemiser SE -
Installation