Bradford White HE-4-50S6FSX - Manual (Page 5)

Page 5
The Bradford White DEFENDER Safety System
®
The Bradford White DEFENDER Safety System was designed to resist the ignition of
flammable 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 design 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 DEFENDER Safety System.
Introduction
The new Bradford White Super High Efficiency atmospheric vent gas 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, and
the Bradford White Defender Safety System.
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 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.
Please read the service manual completely before attempting service on this new series of super
high efficiency gas models.
How the Safety System Works
During normal operation, air for combustion is drawn into the water heater through the
openings 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 bottom. 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
combustion chamber, the vapors are harmlessly ignited by the burner. If flammable vapors are
Introduction
5