Bradford White D-4-504S6FSX - Manual (Page 5)

Page 5
The Bradford White DEFENDER Safety System ®
The Bradford White DEFENDER Safety System was designed to resist the ignition of flamma-
ble vapors that can occur outside of the water heater. Use and installation are nearly identical to
previous versions of atmospherically fired and vented water heaters. A number of exclusive de-
sign features are incorporated in the system that will require additional knowledge on the part of
the qualified service provider. The following information will instruct service professionals on
the function, proper diagnosis, and repair of water heaters employing the Bradford White DE-
FENDER Safety System.
Introduction
The new Bradford White Residential Flue Damper water heaters are designed to provide reli-
able performance with enhanced standard features. New design features include reliable spark-
to-pilot ignition system, enhanced diagnostics, simplified servicing, significantly quiet opera-
tion, and the Bradford White Defender Safety System.
Spark-to-Pilot Ignition System - employing the spark-to-pilot ignition system promotes reli-
able and consistent pilot and main burner ignitions to provide hot water on demand.
Integrated Immersion Thermal Well/Gas Control with LED - was developed for ease of
troubleshooting by providing simple diagnostic codes to pinpoint an installation or component
performance issue.
Rugged Wiring Connections - receptacle type connections promote error free wiring.
The gas control maintains water temperature, ignition sequence, and regulates gas flow. If a
situation outside of normal operating parameters exists, the gas control diagnostic LED will
flash a code to positively identify an operational issue.
This service manual is designed to facilitate problem diagnosis and enhance service efficiency.
To further promote quicker service times, the gas control can be removed and replaced without
draining the water heater. A special tool is required and will be provided with each gas control
kit shipped from your Bradford White wholesale distributor.
Please read the service manual completely before attempting service on this new series of
damper models.
How the Safety System Works
During normal operation, air for combustion is drawn into the water heater through the open-
ings in the jacket. This air travels down and around the combustion chamber and enters through
holes in the very bottom of the corrosion resistant combustion chamber. The air then travels up
through the flame arrestor louvers, where the velocity of the air is increased and its direction
altered. The air then mixes in a normal manner with supplied gas and is efficiently combusted,
producing very low NO
x
emissions.
In the unlikely event trace amounts of flammable vapors are present in the air flowing into the
Introduction
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