Service Manual

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Introduction
The newBradford White U2TW & UTW4water heaters are designed toprovidereliable
performance with enhanced standardfeatures.Newdesign features includereliablespark to
pilot ignition system, enhanceddiagnostics, simplified
servicing, significantly quiet operation
and additionalvent lengths.Inaddition, the U2TW & UTW4water heaters provideUltra Low
NOx emissions.
SparktoPilot Ignition System-employing thespark to pilot ignition systempromotes
reliableand cons
istent pilotand main burner ignitionstoprovide hot water on demand.
Integrated Immersion Thermostat/Gas Control Valve with LED -was developedfor ease
of troubleshooting by providing simple diagnostic codes to pinpointaninstallation or
component performance issu
e.
Powerful Blower - will eliminate problems with difficult venting situations.
Quieter and Cooler Blower Operation - blower noise issignificantly reducedfor both
interiorand exteriorenvironments. Cooler operation increases blower life by reducing bearing
wear and noise
.
RuggedWiring Connections - receptacletype connections promote error free wiring.
IncreasedVent Lengths - increasedventing performance isachieved while maintaining
Energy Factor &FHSR performance.
The U2TW & UTW4w
ater heaters use a combustion systemwhere flue gases are combined
with dilution airto reducethe flue gas temperature in the blower. The diluted flue gases are
evacuated to theexteriorthrough low temperature vent materials. The gas control ma
intains
water temperature, ignition sequenceand regulates gas flow. A safetycircuit consisting of a
pressure switch and blower temperature switch verifies proper conditionsexist forsafeand
reliable operation. If asituation outside of normaloperating parameters exi
sts, the gas control
diagnostic LED will flash a codetopositively identify anoperationalissue.
This service manualis designed tofacilitate problemdiagnosisand enhance serviceefficiency.
Please read the service manual completely before atte
mpting service on this new series of
power vent models.
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