Expansion Vessel And Pressure Gauge; Function; Checks; Removal Of The Expansion Vessel - Biasi Advance Plus 25C ERP Service Manual

13 EXPANSION VESSEL AND PRESSURE
GAUGE

13 .1 Function

The Expansion vessel ("A" in Figure 13.1) function is to allow
for the volume expansion of the C.H. circuit water due to the
temperature rise.
A
Figure 13 .1

13 .2 Checks

1 Turn off the flow and return isolation valves and empty the
primary circuit of the boiler.
2 Remove the protective cap "B" in Figure 13.2 from the valve
on the top of the expansion vessel and connect a suitable air
pressure gauge.
Figure 13 .2
3 Check the pre-load pressure and refer to the section Expan-
sion vessel in the User manual and installation instructions
for the correct value.
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EXPANSION VESSEL AND PRESSURE GAUGE

B

13 .3 Removal of the expansion vessel

Warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent .
1 Remove the front and right hand side panels of the case, turn
off the flow and return isolation valves and empty the primary
circuit.
2 Completely unscrew the connection "C" (Figure 13.3).
3 Unscrew the screws "D" and "E" (Figure 13.3).
4 Remove the expansion vessel from the front of the boiler.
5 Re-assemble the parts in reverse order of removal.
Figure 13 .3
E
D
C