34
Installation and Servicing
SECTION 3 - SERVICING
3.8 CH EXPANSION VESSEL RECHARGING & REPLACEMENT (INDIRECT ONLY)
RECHARGING
1.
Refer to Section 3.4 for front panel removal.
2.
Remove the charge point cover.
3.
Recharge the tank pressure to 0.75 bar.
4.
Re-assemble in reverse order.
5.
Check that the HIU operates in both DHW & CH
modes.
REPLACEMENT
6.
Refer to Section 3.4 for front panel removal.
7.
Drain the HIU CH circuit. Refer to Section 3.5.
8.
Remove the retaining clip on the vessel water
connection pipe and remove the pipe.
9.
Support the expansion vessel and unscrew the 2
screws from the securing bracket, located on the
top of the HIU, and remove.
(Note the position of
the bracket on the vessel).
10.
Remove the expansion vessel.
11.
Fit the new expansion vessel.
12.
Reassemble in reverse order ensuring the seal is
in place.
13.
Refill the HIU and check for leaks. Refer to
Section 2.5.
14.
Check that the HIU operates in both DHW & CH
modes.
RECHARGING
1.
Refer to Section 3.4 for front panel removal.
2.
Remove the charge point cover.
3.
Recharge the tank pressure to 3.5 bar.
4.
Re-assemble in reverse order.
5.
Check that the HIU operates in both DHW & CH
modes.
REPLACEMENT
6.
Refer to Section 3.4 for front panel removal.
7.
Drain the HIU DHW circuit. Refer to Section 3.5.
8.
Using the brass nut at the rear of the hammer
arrestor to unscrew from the manifold.
9.
Remove the water hammer arrestor.
10.
Reassemble in reverse order ensuring the
gasket is in place.
11.
Refill the HIU and check for leaks. Refer to
Section 2.5.
12.
Check that the HIU operates in both DHW & CH
modes.
3.9 DHW WATER HAMMER ARRESTOR RECHARGING & REPLACEMENT
2
9
SER
VICING
