29
OCH714D
WATER SYSTEM DIAGRAM
8
9
31
8
32
34
36
B
33
A
33
34
35
Pa
10
4
24
7
27
6
11
25
18
5
14
12
15
22
19
13
6
23
17
16
32
21
26
3
28
29
42
<E*ST17/20D-*M**D> (Split model system)
Drain
Drain
Cylinder unit
Cold water
DHW
Local system
*a
Water
supply
Water flow
Refrigerant flow
Flare connection
<Figure 8.2>
Notes
• To enable draining of the cylinder unit, an
isolating valve should be positioned on both
the inlet and outlet pipework.
• Be sure to install a strainer on the inlet pipe-
work to the cylinder unit.
• Suitable drain pipework should be attached
to all relief valves in accordance with your
country’s regulations.
• A backflow prevention device must be in
-
stalled on the cold water supply pipework
(IEC 61770)
• When using components made from differ-
ent metals or connecting pipes made of dif-
ferent metals, insulate the joints to prevent
any corrosive reaction taking place which
may damage the pipework.)
*a. Refer to the following section [Local system].
3
9
31
34
34
36
36
34
B
33
A
33
34
35
Pa
10
4
24
7
27
6
11
2
5
18
5
14
12
15
22
19
13
6
23
17
16
6
32
21
26
37
41 *b
42
<Figure 8.1>
<E*PT17X-*M*D> (Packaged model system)
Notes
• To enable draining of the cylinder unit, an
isolating valve should be positioned on
both the inlet and outlet pipework.
• Be sure to install a strainer on the inlet
pipework to the cylinder unit.
• Suitable drain pipework should be attached
to all relief valves in accordance with your
country’s regulations.
• A backflow prevention device must be in
-
stalled on the cold water supply pipework
(IEC 61770)
• When using components made from dif-
ferent metals or connecting pipes made
of different metals, insulate the joints to
prevent any corrosive reaction taking place
which may damage the pipework.)
*a. Refer to the following section [Local system].
*b. If the outdoor unit is higher than the indoor
unit, or if there is a location where air gets
trapped in the upper part of the water pipe,
consider adding this part.
Drain
Drain
Cylinder unit
Cold water
DHW
Local system
*a
Water
supply
Water flow
<EHPT20X-MHEDW> (UK model system) <Example>
*a. Refer to the following section ‘Local sys
-
tem’ on the ‘Paper-based manual’.
Note
• To enable draining of the cylinder unit, an iso-
lating valve should be positioned on both the
inlet and outlet pipework. No valve should be
fitted between the expansion valve (item 38)
and the cylinder unit (safety matter).
• For space heating (primary) circuit a suit-
able expansion vessel
MUST
be supplied
and fitted by installer.
• Be sure to install a strainer on the inlet pipe-
work to the cylinder unit.
• Suitable drain pipework should be attached
to all relief valves in accordance with your
country’s regulations.
• When using components made from differ-
ent metals or connecting pipes made of dif-
ferent metals, insulate the joints to prevent
any corrosive reaction taking place which
may damage any pipework.
• Filling loop’s flexible hose must be removed
following the filling procedure. Item provided
with unit as loose accessory.
• Install the inlet control group (item 38)
above the level of the T&P relief valve (item
20). This will ensure DHW tank will not
require drain down to service/maintain the
inlet control group.
Flexible hose
(Temporary connection)
Mains water supply
37
41*b
3
12
31
39
34
34
35
34
36
36
9
34
B
32
32
38
A
Pa
24
27
25
18
5
15
22
19
6
7
23
17
16
20
11
14
13
40
6
6
26
10
<Figure 8.3>
Drain
Drain
Cylinder unit
Cold water
DHW
Local system
*a
Water flow
Drain
