Notes on installation and operation
43
Greenstar – 6721822579 (2021/01)
Table 18 Vent and combustion air pipe lengths with 2" diameter and the
stainless steel wall termination
Table 19 Vent and combustion air pipe lengths with 2" diameter and the
concentric termination
Ø 3" / Ø 5" (Ø 80/125 mm) Concentric venting system
The maximum total concentric pipe length (
tab. 20) depends on the
installation situation, the appliance type and the number of elbows used.
Table 20 Pipe lengths with Ø 3" / Ø 5" (Ø 80/125 mm) diameter and
termination
Table 21 Concentric pipe friction loss equivalent for fittings
Example:
• Model:
ZBR 28-3A
• 90° elbows used:
2
• 45° elbows used:
2
Maximum straight vent pipe allowed:
38ft (11.6 m)
6.9
Testing gas and water connections for leaks
NOTICE
Pressure, control and safety equipment may be damaged by
excessive pressure.
▶ When you carry out a leakage test, make sure that no pressure,
control or safety equipment is installed that cannot be isolated from
the test pressure.
▶ The boiler and its dedicated shutoff valve must be disconnected from
the gas supply piping system during any pressure testing of that
system at test pressures in excess of 14" W.C. (35 mbar).
Water connections
▶ Open the heating supply and return valves and fill the heating system.
▶ Check all connections for leakage (test pressure: Max. 30 psi (2.07
bar) on the pressure gauge).
Gas line
▶ Close the gas shutoff valve to protect the gas valve from damage.
▶ Check all connections for leakage (test pressure: Max. 60" W.C.
(150 mbar)).
▶ Release pressure.
Installations
Fig. 35 Stainless steel wall termination
2" PIPE
Maximum straight vent pipe length
allowed for Ø 2" pipe
Number of 90° elbows
used
ZBR 21-3A
ZBR 28-3A
ZWB 28-3A
ZBR 35-3A
ZWB 35-3A
ZBR 42-3A
ZWB 42-3A
1
76 ft (23.1 m)
60 ft (18.3 m)
2
71 ft (21.6 m)
52 ft (15.9 m)
3
66 ft (20.1 m)
43 ft (13.1 m)
4
61 ft (18.6 m)
35 ft (10.7 m)
5
56 ft (17.1 m)
27 ft (8.2 m)
6
51 ft (15.6 m)
18 ft (5.5 m)
Installations
Fig. 38 Concentric termination
2" PIPE
Maximum straight vent pipe length
allowed for Ø 2" pipe
Number of 90° elbows
used
ZBR 21-3A
ZBR 28-3A
ZWB 28-3A
ZBR 35-3A
ZWB 35-3A
ZBR 42-3A
ZWB 42-3A
1
66 ft (20.1 m)
47 ft (14.3 m)
2
61 ft (18.6 m)
38 ft (11.6 m)
3
56 ft (17.1 m)
30 ft (9.1 m)
4
51 ft (15.6 m)
22 ft (6.7 m)
5
46 ft (14.1 m)
13 ft (4.0 m)
6
41 ft (12.5 m)
5 ft (1.5 m)
Installations
Fig. 41
Ø 3" / Ø 5" (Ø 80/125 mm)
CONCENTRIC PIPE
Maximum straight vent pipe length
allowed for Ø 3" / Ø 5" (Ø 80/125
mm) concentric pipe
Number of 90° elbows used
ZBR 21-3A
ZBR 28-3A
ZWB 28-3A
ZBR 35-3A
ZWB 35-3A
ZBR 42-3A
ZWB 42-3A
1
50 ft (15.2 m)
44 ft (13.4 m)
2
44 ft (13.4 m)
38 ft (11.6 m)
3
38 ft (11.6 m)
32 ft (9.8 m)
4
32 ft (9.8 m)
26 ft (7.9 m)
5
26 ft (7.9 m)
20 ft (6.1 m)
6
20 ft (6.1 m)
14 ft (4.3 m)
Fitting
Equivalent
ft
m
45° elbow
3
0.91
90° elbow
6
1.82