Bosch Greenstar combi 151 p - Testing Gas and Water Connections for Leaks

Notes on installation and operation | 31
6720872361 (2017/04)Greenstar combi 100 p / 151 p
2" (50 mm) Vent and combustion air pipe
The maximum total combined equivalent length of vent and combustion
air pipe ( Tab. 15, 16 and 17) depends on the installation, the
appliance type and number of elbows be used.
Table 15 Vent and combustion air pipe lengths with 2" diameter and
separate terminations
Table 16 Vent and combustion air pipe lengths with 2" diameter and the
stainless steel wall termination
Table 17 Vent and combustion air pipe lengths with 2" diameter and the
concentric termination
3" / 5" (80/125 mm) Concentric venting system
The maximum length of concentric vent or combustion air pipe
( Tab. 18) depends on the installation, the appliance type and number
of elbows used.
Table 18 Pipe lengths with 3" / 5" (80/125 mm) diameter and
termination
Table 19 Concentric pipe friction loss equivalent for fittings
Example:
• Model: combi 151 p
• 90 ° elbows used: 2
• 45 ° elbows used: 2
Maximum length of straight pipe: 32 ft (9.8 m)
6.8 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.
Installation  Fig. 25, 26, 27, 29, 30 and 32 separate terminal
ends
2" PIPE Maximum straight vent pipe length
allowed for Ø 2" pipe
Number of 90 ° elbows
used
combi 100 p combi 151 p
1 81 ft (24.6 m) 65 ft (19.8 m)
2 76 ft (23.1 m) 57 ft (17.3 m)
3 71 ft (21.6 m) 48 ft (14.6 m)
4 66 ft (20.1 m) 40 ft (12.2 m)
5 61 ft (18.6 m) 32 ft (9.8 m)
6 56 ft (17.1 m) 23 ft (7.0 m)
Installation  Fig. 28 Stainless steel terminal end, horizontal
2" PIPE Maximum straight vent pipe length
allowed for Ø 2" pipe
Number of 90 ° elbows
used
combi 100 p combi 151 p
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)
Installation  Fig 31 Concentric terminal end
2" PIPE Maximum straight vent pipe length
allowed for Ø 2" pipe
Number of 90 ° elbows
used
combi 100 p combi 151 p
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)
Installation  Fig. 34
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 combi 100 p combi 151 p
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