Parts Replacement; Initial Preparation - Vaillant TURBOmax VUW 242 E Instructions For Installation And Servicing

7. Parts replacement

IMPORTANT:
Before starting any maintenance
work:
•
Isolate the mains electricity supply
by disconnecting the plug at the
socket outlet (if there is an isolating
switch only, remove the fuse from
the switch).
•
When removing any water carrying
components ensure that the control
box cover and terminal box cover
are in position and water is kept
away from all electrical
components.
•
Turn OFF the gas supply at the gas
service valve fitted to the boiler.
•
Always test for gas soundness and
always carry out functional checks
after any service work and after
exchanging any gas carrying
component.
•
Always check earth continuity,
polarity and resistance to earth with
a multimeter after any service work
and after exchanging any electrical
component.

7.1 Initial preparation

(These initial preparation procedures
need only be carried out where
specifically mentioned in the individual
component replacement procedures).
7.1.1 Turning off the boiler (fig. 50)
•
Isolate the electrical supply to the
boiler
•
Turn off the gas service valve (1)
•
Turn off boiler CH service valves (2)
•
Turn off DHW cold water service
valve (3).
32
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7.1.2 Releasing CH water pressure
and draining the boiler (fig. 50)
•
Isolate electrical supply to boiler.
•
Remove combustion chamber cover
as in section 7.1.5.
•
Turn off boiler CH service valves
(2).
•
Attach a length of rubber tube to
draining points (4), and drain the
water from the boiler into a
suitable container by undoing the
drain points one turn.
•
When pressure gauge reads zero,
open main heat exchanger air vent
(5, fig. 57) to allow complete
draining of the boiler. Close air
vent before refilling the boiler.
fig. 50