Freestyle 2 Series - Page 51

Part number 550-142-950/0122
51
FreeStyle
®
series 2 wall mount gas-fired water boiler – boiler manual
Gas Rate (Natural Gas)
After 10 minutes from cold
Combi
Boiler
model
Maximum rate Minimum rate
ft
3
/h ft
3
/h
FS-80
78.4 7.8
FS-120
117.6 11.8
FS-155
151.9 15.2
Table 2 Gas rate for Combi and Heating Only boilers
Measure the gas rate
Measure the gas rate and check against following Table 2:
For natural gas or liqueed petroleum (propane) gas, the pressure
required at gas valve inlet pressure port (verify minimum gas
pressure when all gas appliances are in operation):
a. Maximum: 13” w.c. with no ow (lockup) or with boiler
on.
b. Minimum gas pressure, with gas owing (verify during
boiler startup, while boiler is at high re)
— FreeStyle® 80: 3.5” w.c.;
— FreeStyle® 120: 3.5” w.c.;
— FreeStyle® 155: 3.5” w.c.
c. Nominal gas pressure: 11.0” w.c.
4. Install 100% lockup gas pressure regulator in supply
line if inlet pressure can exceed 13” w.c. at any time.
Adjust lockup regulator for 13” w.c. maximum.
21 Gas piping (continued)
Gas pipe sizing
1. See page14 for gas line sizing information.
Check gas pressure at inlet to boiler
1. See Figure64 for location of the gas inlet pressure test port.
Check the operational (working) gas inlet
pressure
1. Set up the boiler to operate at maximum rate as described in
section“ Test mode” Figure104,page79.
2. With the boiler operating at maximum rate check that the op-
erational (working) gas pressure at the inlet gas pressure test
port (see above) complies with the requirements of Table 2 .
3. Ensure that this inlet pressure can be obtained with all other
gas appliances in the property working.
Figure 64 Inlet test port on gas valve
Inlet test port