Gas Pressure; Gas Valve Replacement - Lochinvar CREST 102 Series Supplemental Manual

1
Gas connections
Do not check for gas leaks with an open
⚠WARNING
flame -- use the bubble test.
use the bubble test or check for gas leaks
can cause severe personal injury, death, or
substantial property damage.
10.
If the gas pressure is out of range, contact the gas utility,
gas supplier, qualified installer, or service agency to
determine the necessary steps to provide proper gas
pressure to the control.
11.
Turn the power switch to the "OFF" position.
12.
Shut off the gas supply at the manual gas valve in the gas
piping to the appliance.
13.
Remove the manometer from the pressure tap on the
gas manifold or gas valve flange, depending on model
size. Remove the 1/8" (3mm) field supplied fitting and
reinstall the pipe plug removed in Step 3.
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 TOUCH 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 flame characteristics.
18. Repeat Steps 1 - 17 for both natural and LP gas supply.
Figure 1-1 Inlet Gas Supply Check_Natural - Models
751-2001
Figure 1-3 Inlet Gas Supply Check_Natural - Models
2501-6001
(continued)
Failure to
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Dual Fuel Supplemental Manual
Ignition problems are 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, the gas valves have flanged
connections to the venturis and blowers.
Failure to follow all precautions
⚠WARNING
could result in fire, explosion, or
death!
DO NOT adjust or attempt to
⚠WARNING
measure gas valve outlet pressure.
Attempting 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.

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. (1.99 kPa) minimum and 14
inches w.c. (3.5 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 Crest 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.
Figure 1-2 Inlet Gas Supply Check_Propane - Models
751-2001
Figure 1-4 Inlet Gas Supply Check_Propane - Models
2501-6001
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