High-Efficiency Commercial Gas Series - Service Manual
Technical Literature Department
7
Ashland City, Tennessee © 2008
Servicing should only be performed by a Qualified Service Agent
GAS PRESSURES 199 and 250 KBtu/hr MODELS
ADJUSTMENT PROCEDURE:
GAS PRESSURE
199 AND 250 MODELS
THE 199 AND 250 MODELS
INCORPORATE A NEW GAS CONTROL,
WHICH OPERATES AT A MANIFOLD
PRESSURE OF 0"W.C. (0 kPa) FOR BOTH
NATURAL AND PROPANE GAS. SEE THE
GAS PRESSURE CHART ON PAGE 4.
THESE MODELS ARE FACTORY SET, NO
MANIFOLD GAS PRESSURE
ADJUSTMENTS ARE NECESSARY PRIOR
TO STARTUP.
Verify supply gas pressure is within the
requirements given in the Instruction Manual
that came with the water heater and shown
in the table on page 4 prior to start up.The
inlet gas pressure must not exceed the
maximum values.
HIGH ALTITUDE INSTALLATION
The 199 and 250 models are suitable for
installation up to 10,100 feet above sea level
with no adjustments.
GAS ORIFICE
The 199 and 250 models do not have a
natural gas orifice. A .230” orifice is used on
LP gas models.
A supply gas pressure regulator
(service regulator) must be installed on
the gas supply line within 10' (305 cm)
of the unit.
IMPORTANT NOTE
Gas Control with .230” LP Orifice
Venturi
Gasket w/
LP Gas
Orifice
(.230”
Brass)
Gas Control Without Orifice
Natural Gas
Venturi
Gasket w/
o orifice
