Install Instructions

42
6 Gas connections
Gas pressure
The gas pressure must remain between 4 inches w.c. (natural),
8 inches w.c. (LP) minimum and 14 inches w.c. (natural and
LP) maximum during stand-by (static) mode and while in
operating (dynamic) mode. If an in-line regulator is used, it
must be a minimum of 10 feet from the Shield water heater.
It is very important that the gas line is properly purged by the
gas supplier or utility company. Failure to properly purge the
lines or improper line sizing, will result in ignition failure.
The problem is especially noticeable in NEW LP installations
and also in empty tank situations. This can also occur when
a utility company shuts off service to an area to provide
maintenance to their lines.
IMG00477
LOOSEN THE SET SCREW ONE (1) FULL TURN AND
PLACE THE MANOMETER TUBING OVER THE
PRESSURE TAP
DETAIL
Figure 6-4 Inlet Gas Supply Check - Models 126-065
-- 286-125
DETAIL
LOOSEN THE SET SCREW ONE (1) FULL TURN AND
PLACE THE MANOMETER TUBING OVER THE
PRESSURE TAP
IMG00479
Figure 6-5 Inlet Gas Supply Check - Model 401-125
IMG00479
LOOSEN THE SET SCREW ONE (1) FULL TURN AND
PLACE THE MANOMETER TUBING OVER THE
PRESSURE TAP
DETAIL
Figure 6-6 Inlet Gas Supply Check - Model 501-125
DO NOT 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
(when configured for LP), requiring no
field adjustment. Attempting to measure
the gas valve outlet pressure could
result in damage to the valve, causing
potential severe personal injury, death, or
substantial property damage.
Failure to follow all precautions could
result in fire, explosion, or death!
 WARNING
 WARNING
Gas valve replacement
The gas valve MUST NOT be replaced with a conventional
gas valve under any circumstances. As an additional safety
feature, this gas valve has a flanged connection to the venturi
and blower.
17. Check burner performance by cycling the system while
you observe burner response. The burner should ignite
promptly. Flame pattern should be stable. Turn system
off and allow burner to cool, then cycle burner again to
ensure proper ignition and flame characteristics.
Installation & Service Manual