Boiler Return Sensor (Ntc); Drain Tap; Ch Pressure Relief Valve; Hydraulic Block Removal - Worcester 27i System Compact Installation, Commissioning And Servicing Instructions

6.8.18 BOILER RETURN SENSOR (NTC)

▶ Isolate the boiler and ensure that the system is fully drained.
1. Withdraw the spring clip to release the sensor.
2. Pull the sensor down to remove from the housing.
▶ To refit follow the above actions in reverse.
Fig. 106 Boiler return sensor

6.8.19 DRAIN TAP

▶ Ensure that the system is full drained down.
▶ The drain tap rotates anti-clockwise for a ¼ turn to open.
1. Rotate the drain tap anti-clockwise passed the ¼ turn stop point to
release.
2. Push in and withdraw from the housing.
1.
2.
Fig. 107 Drain tap

6.8.20 CH PRESSURE RELIEF VALVE

▶ Isolate the boiler and ensure that the boiler is fully drained.
1. Release the knurled connector from the bottom of the PRV.
2. Pull the captive clip to the left to release the PRV.
3. Pull the Central Heating pressure relief valve out of the housing.
▶ Replace in reverse order, secure with the clip and mounting screws.
Greenstar i System Compact - 6 720 807 726 (2013/05)
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Fig. 108 PRV

6.8.21 HYDRAULIC BLOCK REMOVAL

Do not remove the hydraulic block assembly unless
absolutely necessary.
Before removal:
▶ Isolate the electrical power to the boiler.
▶ Drain the system.
1. Squeeze the ratchet connector and rotate clockwise to release.
2. Release the clip on the expansion vessel connector at the pump
assembly.
3. Pull the expansion vessel up and secure in raised position.
4. Remove the clip securing the pump return to the heat exchanger.
5. Remove the two screws securing the CH pressure relief valve
mounting.
6. Remove the screws securing the hydraulic block assembly.
1.
6.
Fig. 109 Hydraulic block
SERVICE AND SPARES
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