Pressure Relief Valve; Bypass Valve; Expansion Vessel - Bosch Condens 5000W Installation And Maintenance Instructions Manual

6.8.23 CH pressure relief valve
▶ Remove the hydraulic block from the boiler (see removing the
hydraulic block).
1. Release the spring clip from the pressure relief valve housing.
2. Withdraw the pressure release valve from its housing.
2.
Fig. 113 PRV removal
▶ To refit, follow the above in reverse. Ensure any seals that have been
disturbed are renewed.

6.8.24 Bypass valve

1. Remove the two spring clips at either end of the copper bypass pipe.
▶ Undo the screw securing the left hand plastic housing to the heat
exchanger.
▶ Move the housing to the left to free up the one end of the pipe.
▶ Remove the pipe from the right hand housing to reveal the bypass
valve.
2. Remove the two spring clips at either end of the copper bypass pipe.
1.
Fig. 114 Removing the bypass valve
▶ To refit, follow the above in reverse. Ensure any seals renewed.
Bosch Condens 5000W – 6 720 646 195 (2018/10)
1.
6720644743-36.1Wo
2.
6720644743-37.1Wo

6.8.25 Expansion vessel

The expansion vessel can be replaced with the boiler in position if there
is a side exit flue fitted and a minimum clearance of 340mm above the
boiler casing. If a vertical flue is fitted then a similar clearance to one side
of the flue is required.
If this clearance is not available, then the boiler will need to be removed
from the mounting frame to gain access to the expansion vessel.
Alternatively a second vessel of at least the capacity of seven litres can
be fitted to the return from the heating system as close as possible to the
boiler.
Expansion vessel replacement (boiler in place)
▶ Isolate mains power from the boiler.
▶ Lower the control panel to the service position.
▶ Isolate the boiler from the heating system (and cylinder return if
internal diverter valve is fitted) using service valves.
▶ Drain the boiler.
▶ At the pump manifold, release the clip and disconnect the expansion
vessel hose.
Refer to figure 115.
1. Remove screw [1] retaining the vessel to the top of the boiler casing.
2. Move the vessel up [2] and out over the flue system or to one side if
fitted with a vertical flue.
1.
Fig. 115 Removing the expansion vessel
▶ Remove the flexible hose from the expansion vessel and fit to the
replacement vessel using a new seal.
▶ Reassemble expansion vessel into wall frame and reconnect the
flexible pipe to pump manifold and secure with the clip.
Servicing and spares
2.
53