Gas Pressure; Gas Valve Replacement - Lochinvar FTxl 400 Installation & Operation Manual

7
Gas connections
When re-tightening the set screw, be sure
WARNING
to tighten securely to prevent gas leaks.
Do not check for gas leaks with an open
fl ame -- use the bubble test. Failure to
use the bubble test or check for gas leaks
can cause severe personal injury, death, or
substantial property damage.
14. Turn on the gas supply at the manual gas valve.
15. Turn the power switch to the "ON" position.
16. Adjust the temperature set point on the control panel of
the SMART SYSTEM control module to the desired
water temperature so the appliance will call for heat.
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 fl ame characteristics.
Figure 7-5 Inlet Gas Supply Check - Model 400 - 500
Figure 7-6 Inlet Gas Supply Check - Models 600 - 850
(continued)

Gas pressure

The gas pressure must remain between 4 inches w.c.
(.99 kPa) minimum and 14 inches w.c. (3.5 kPa) maximum
for Natural gas and between 8 inches w.c. (1.9 kPa) minimum
and 14 inches w.c. (3.2 kPa) maximum for LP gas during
standby (static) mode and while in operating (dynamic)
mode. If an in-line regulator is used, it must be a minimum
of 10 feet (3 m) from the FTXL boiler. 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.

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 fl anged connection to the venturi
and blower.
WARNING
WARNING
Installation & Operation Manual
Failure to follow all precautions could
result in fi re, explosion, or death!
DO NOT adjust gas valve outlet pressure.
Attempting to alter the gas valve outlet
pressure could result in damage to the
valve, causing potential severe personal
injury, death, or substantial property
damage.
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