Cleaning The Primary Strainer; Replacing Components - Worcester Greenstar HIU Installation And Maintenance Instructions Manual

Inspection and service
10.2

Cleaning the primary strainer

Draining the appliance
To drain the primary circuit and the heating system:
▶ Disconnect heat interface unit with shut-off valves from the primary
circuit and the heating system.
▶ Connect hose [3] to the drain valve.
To drain the heat interface unit:
▶ Open the air vents at the top of the desired circuit.
▶ Close the air vents again after draining!
▶ Turn the drain valve [1] anti-clockwise to open [2].
1
3
Fig. 37 Drain point connection
Remove the strainer in the primary circuit
▶ Remove the drainage assembly from the connection [2].
▶ Replace the gasket [3] if required.
▶ Clean the strainer [1].
3
Fig. 38 Remove and clean the strainer
10.3

Replacing components

Draining the appliance
To drain the primary circuit and the heating system:
▶ Disconnect heat interface unit with shut-off valves from the primary
circuit and the heating system.
▶ Connect hose [3] to the drain valve.
To drain the heat interface unit:
▶ Open the air vents at the top of the desired circuit.
20
2
1
2
0010018673-01 0010018673-01
▶ Close the air vents again after draining!
▶ Turn the drain valve [1] anti-clockwise to open [2].
1
3
Fig. 39 Drain point connection
To drain the domestic water system:
▶ Isolate the cold mains inlet isolation valve.
▶ Drain the domestic water system.
Heat exchanger
NOTICE
Material damage and leaks due to incorrect installation!
If the retention bracket is loosened or tightened unevenly this could
cause damage and leaks.
▶ Loosen or tighten the screws on the retention brackets evenly.
▶ Drain the HIU completely.
▶ Loosen the screws on the retention brackets [2] evenly.
▶ Pull the retention brackets off the heat exchanger [1].
▶ Replace the gaskets [3] of the connecting plates [4, 5] if required.
▶ Install the new heat exchanger so the arrow points towards the centre
of the appliance.
▶ Purge the system correctly and check for leaks.
▶ Vent water circuits sufficiently (follow the procedure set out in the
commissioning instructions).
5
3
4
0010032049-01 0010032049-01
Fig. 40 Removing the heat exchanger
Control valves
▶ Drain the HIU completely.
2
1
2
Greenstar – 6721852556 (2022/11)