Gas Supply And Piping - Williams FORSAIRE 4007332 Owner's Manual

INSTALLING YOUR FURNACE

Gas Supply and Piping

Gas control valve, within the furnace, is shipped with a seal
over the gas inlet tapping. Do not remove seal until ready
to connect piping.
WARNING: Danger of property damage, bodily
injury or death. Make sure the furnace is equipped
to operate on the type of gas available. Models
designated as natural gas are to be used with
natural gas only. Furnace designated for use with
liquefied petroleum propane gas rate orifices sized for
commercially pure propane gas. They cannot be used
with butane or a mixture of butane and propane.
GAS SUPPLY
For Natural gas, the minimum inlet gas supply pressure for
the purpose of input adjustment is 5" water column. The
Maximum inlet gas supply pressure is 7" water column.
For propane gas, the minimum inlet gas supply pressure
for the purpose of input adjustment is 11" water column. The
maximum inlet gas supply pressure is 13" water column.
Gas pressure and input to the burners must not exceed
the rated input and pressure shown on the rating plate.
On Natural Gas the manifold pressure should be 4 inches
water column. The manifold pressure should be 10.5
inches water column for propaned gas. See page 19 for
operation above 2,000 feet altitude. Orifice change may
be required to suit gas supplied. Check with your local
gas supplier.
ORIFICE SIZES
Furnace Technical Information, page 25, shows the correct
orifice sizes for the different input ratings when using
Natural or propane gas.
GAS PIPING
The gas supply line must be of adequate size to handle
the BTU/hr. requirements and length of the run for the
unit being installed.
Determine the minimum pipe size from Page 16, Figure
24, basing the length of the run from the gas meter or
source to the unit.
All piping must comply with local codes and ordinances or
with the National Fuel Gas Code (ANSI Z223.1), whichever
applies. In Canada: Follow CAN 1(B149 Installation Code.
Refer to Page 15, Figure 21, for the general layout at the
unit. It shows the basic fittings needed.
16
FORSAIRE COUNTERFLOW DIRECT VENT GAS WALL HEATER
FIGURE 24 - LEFT SIDE GAS INLET
FIGURE 25 – PROPER PIPING PRACTICE
PROPER PIPE
THREADING
INCORRECT
THREADING
OVER-THREADED
2 THREADS EXPOSED
SEALANT THIN
ENOUGH TO SHOW
THREADS
DAMAGED
SEALANT
THREADS
PAST TIP
SEALANT
TOO THICK