Bosch Worcester GREENSTAR 12i System Instruction Manual page 50

49
REPLACEMENT OF PARTS
26.1
A
INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER BOSCH GREENSTAR 12i System/24i System
25.1 REPLACEMENT OF PARTS
25. Hydraulic Block
Ensure the appliance has been fully drained
(see draining the appliance).
Disconnect the electrical connections to the
pump.
Undo the nuts securing the copper water
pipes to the manifold (there is no need to
remove the gas pipe)
Release the spring clips securing these
water pipes to the plastic housing and
remove the pipes.
Release the spring clip securing the
expansion vessel pipe to the plastic housing
and remove the pipe.
Undo the nut securing the pressure gauge to
25.2
its bracket and remove the gauge.
Release the locking devices that secure the
two copper water pipes leading to the
combustion chamber by squeezing the two
tabs together and rotating anticlockwise
(viewed from above).
Remove the rubber pipe connecting the
sump and remove the sump. NOTE: this is
not essential but makes the removal of the
block easier.
25.1 Undo the two screws securing the hydraulic
block to the chassis (located top left / top
right of the housing)
25.2 Lift the left hand side of the block slightly,
then manoeuvre the block out, starting with
the right hand side.
Take care not to snag the harness or
pressure gauge bracket.
NOTE: the block will still contain a small amount
of water, which will spill if the block is tilted.
To refit, follow the above in reverse. Ensure
any seals that have been disturbed are
renewed.
26. CH pressure relief valve
Remove the hydraulic block from the boiler
(See Removing the Hydraulic Block).
26.1 Remove the spring clip from the pressure
relief valve housing.
26.2 Withdraw the pressure release valve (A) from
its housing.
To refit, follow the above in reverse. Ensure
any seals that have been disturbed are
renewed.
26.2
8 716 107 375a (02/05)