Replacing The Gas Valve; Replacing The Prv; Replacing The Expansion Vessel; Replacing The Pressure Sensor - Worcester Greenstar 4000 Installation And Maintenance Instructions Manual

Replacement parts
9.6

Replacing the gas valve

▶ Close the gas isolator.
▶ Unscrew the union nut [1].
▶ Remove the connector [2].
▶ Unscrew the union nut [3].
▶ Remove the union nut and hose connection [4] from gas valve.
▶ Remove the 2 screws [6].
▶ Remove the gas valve [5].
1
2
3
Fig. 92 Removing the gas valve
▶ Install the gas valve in reverse order, and check the gas/air ratio.
9.7

Replacing the expansion vessel

▶ Disconnect the pipe union nut [3].
▶ Slacken the screws on the clamps, top [1] and bottom [2] of the
expansion vessel.
▶ Slide the expansion vessel [4] towards you to remove.
3
Fig. 93
▶ Replace the expansion vessel in the reverse order
68
4
5
6
1
4
2
9.8

Replacing the PRV

▶ Unscrew the knurled nut of the PRV discharge pipe.
▶ Disconnect the PRV discharge pipe prior to removing the PRV.
▶ Remove the PRV in the sequence shown.
– Release the clip.
– Pull the PRV forward to release.
2.
Fig. 94 PRV removal
▶ Replace the PRV in the reverse order
9.9

Replacing the pressure sensor

Pressure sensor is a wet pocket sensor, therefore the appliance must be
drained down.
▶ Remove the pressure sensor in the sequence shown.
– Release the electrical connection clip [1].
– Disconnect the electrical connection [2].
– Release the clip [3].
– Pull the pressure sensor forward to release [4].
1.
Fig. 95 Pressure sensor removal
▶ Replace the pressure sensor in the reverse order
Greenstar 4000 – 6 720 891 162 (2020/09)
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0010036566-001
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