Bradford White UPDX2-75T6FRN - Manual (Page 4)

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UPDX Series
Introduction
The new Bradford White UPDX2 water heaters are designed to provide reliable performance
with enhanced standard features. New design features include reliable spark to pilot ignition
system, enhanced diagnostics, simplified servicing, significantly quieter operation, additional
vent lengths, certified FVIR technology and Ultra Low NOx emissions.
Spark to Pilot Ignition System - Employing the spark to pilot ignition system promotes
reliable and consistent pilot and main burner ignitions to provide hot water on demand.
Integrated Immersion Thermostat/Gas Control Valve with LED - Was developed for ease
of troubleshooting by providing simple diagnostic codes to pinpoint an installation or
component performance issue.
Powerful Blower - Will eliminate problems with difficult venting situations.
Quieter and Cooler Blower Operation - Blower noise is significantly reduced for both
interior and exterior environments. Cooler operation increases blower life by reducing bearing
wear and noise.
Rugged Wiring Connections - Receptacle type connections promote error free wiring.
Increased Vent Lengths - Increased venting performance is achieved while maintaining
Energy Factor & First Hour Supply performance.
The UPDX2 water heaters use a combustion system where flue gases are combined with
dilution air to reduce the flue gas temperature in the blower, combustion air and dilution air are
drawn from outside the building. The diluted flue gases are evacuated to the exterior through
low temperature vent materials. The gas control maintains water temperature, ignition
sequence and regulates gas flow. A safety circuit consisting of a pressure switch and blower
temperature switch verifies proper conditions exist for safe and reliable operation. If a situation
outside of normal operating parameters exists, the gas control diagnostic LED will flash a code
to identify an operational issue.
This service manual is designed to facilitate problem diagnosis and enhance service efficiency.
To further promote quicker service times the new gas control can be removed and replaced
without draining the water heater. A special tool is required and will be provided with each gas
valve kit shipped from our Service Parts department.
Please read the service manual completely before attempting service on this new series of
power direct vent models.
How the Safety System Works
During normal operation, air for combustion is drawn into the water heater through the intake
vent pipe from outside your building. The air travels into the closed combustion chamber. The
air then mixes in a normal manner with supplied gas and is efficiently combusted, producing
Ultra Low NOx emissions.
In the unlikely event trace amounts of flammable vapors are present in the area surrounding the
water heater, the sealed combustion system prevents the flammable vapors from reaching the
ignition source. In addition the flammable vapor sensor will stop the water heater from
operating if a significant amount of flammable vapors are present.
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