Bradford White TW4-75S-76B-3X - Manual (Page 4)

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Introduction
The new Bradford White TTW2 & TW4 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 quiet operation
and additional vent lengths.
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.
New 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 & FHSR performance.
The TTW2 & TW4 water heaters use a combustion system were flue gases are combined with
dilution air to reduce the flue gas temperature in the blower. 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 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 new gas valve 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 vent models.
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