Figure 33 - Weil-McLain 4 Series Manual

®
Series 4
Gas piping
Connecting gas supply piping
1. Remove jacket front panel and refer to Figure 33 to pipe gas to
boiler.
a. Install ground joint union for servicing, when required.
b. Install manual shutoff valve in gas supply piping outside
boiler jacket when required by local codes or utility require-
ments.
c. In Canada — When using manual main shutoff valve, it must
be identifi ed by the installer.
2. Wall-mounted boilers
a. Refer to separate Ultra Boiler Wall-mounting instructions.
b. Gas connection may enter from the bottom of boiler as
explained in the Wall-mounting instructions.
3. Support piping with hangers, not by boiler or its accessories.
4. Purge all air from gas supply piping.
5. Before placing boiler in operation, check boiler and its gas con-
nection for leaks.
a. Close manual main shutoff valve during any pressure testing
at less than 13" w.c.
b. Disconnect boiler and gas valve from gas supply piping dur-
ing any pressure testing greater than 13" w.c.
Do not check for gas leaks with an open fl ame — use
bubble test. Failure to use bubble test or check for gas
leaks can cause severe personal injury, death or sub-
stantial property damage.
6. Use pipe dope compatible with propane gases. Apply sparingly
only to male threads of pipe joints so that pipe dope does not
block gas fl ow.
Failure to apply pipe dope as detailed above can result
in severe personal injury, death or substantial property
damage.
DO NOT adjust or attempt to measure gas valve outlet
pressure. The gas valve is factory-set for the correct
outlet pressure. This setting is suitable for natural gas
and propane, requiring no fi eld adjustment. Attempt-
ing to alter or measure the gas valve outlet pressure
could result in damage to the valve, causing potential
severe personal injury, death or substantial property
damage.
Ultra boilers are shipped ready to fi re natural gas ONLY.
(Exception: Ultra-80LP is propane-ready.) You must
install the propane orifi ce if the boiler will be connected
to propane. See page 48 . Failure to comply could result
in severe personal injury, death or substantial property
damage.
Gas pipe sizing
1. See page 93 for gas line sizing information.
Check gas pressure at inlet to boiler
1. See Figure 39, page 40 , Figure 40, page 40 , or Figure 41, page 41
for location of the gas inlet pressure test port.
Part number 550-100-400/0119
gas-fired water boiler — Boiler Manual
Use two wrenches when tightening gas
piping at boiler, using one wrench to pre-
vent the boiler gas line connection from
turning. Failure to support the boiler gas
connection pipe to prevent it from turn-
ing could damage gas line components.

Figure 33

Natural gas supply pressure
1. Pressure required at gas valve inlet pressure port:
a. Maximum: 13" w.c. with no fl ow (lockup) or with
boiler on
b. Minimum: 4" w.c. (for all except 5" for -299/310)
with gas fl owing (verify during boiler startup, while
boiler is at high fi re)
2. 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.
Propane supply pressure
1. Adjust propane supply regulator provided by gas sup-
plier for 13" w.c. maximum pressure.
2. Pressure required at gas valve inlet pressure port:
a. Maximum: 13" w.c. with no fl ow (lockup) or with
boiler on
b. Minimum: 4" w.c. with gas fl owing (verify during
boiler startup, while boiler is at high fi re).
29