Section Iii: General Information - Bradford White EF120T Installation & Operation Manual With Troubleshooting Manual

SECTION III: GENERAL INFORMATION

This water heater contains the following features:
Main Power On/Off Switch
The front panel of this water heater has an ON/OFF switch, which has markings to indicate whether the main power to the
water heater is turned on or off.
Combustion System
This water heater is equipped with a self-compensating negative pressure pre-mix combustion system. As the blower
operates, air is drawn in through the air intake and into a venturi, which pulls gas from the gas valve. The gas and air are
then mixed in the combustion blower and sent through the transition tube into the burner. The Direct Spark Ignition (DSI)
System then ignites the gas/air fuel mixture to produce flue products (combustion). The flame sensor signals the ignition
control board (described below) that a flame is present.
Honeywell Integrated Control
The Integrated Control System consists of a control board and a digital water heater display. The digital water heater
display is on the top front of the water heater for setting and displaying the temperature setpoint and monitoring the status
of the water heater. Pressing the temperature UP and DOWN buttons changes the temperature setpoint. The temperature
format may be displayed in degrees F or degrees C. The water heater display will show diagnostic codes in the event the
water heater needs servicing. The temperature readings of the tank sensor can be monitored in Service Mode. The
display can show up to 10 previous error codes in Service Mode to further aid in servicing the water heater.
The single control board has plug in wiring harnesses to reduce the chance of mis-wiring. The control board controls the
combustion blower, ignition timings, and gas valve to run the combustion system in order to maintain the desired tank
temperature. The sequence of operations is described in detail in the Diagnostic Section (page 52).
Adjustable Thermostat
This water heater is equipped with an adjustable thermostat as part of the Integrated Control System to control water
temperature. Hot water temperatures required for automatic dishwasher and laundry use can cause scald burns resulting
in serious personal injury and/or death.
The temperature may be adjusted from about 100°F (38°C) to about 180°F (82°C). The thermostat was adjusted to 100°F
(38°C) before the water heater was shipped from the factory. It is recommended that lower temperatures be used to avoid
the risk of scalding. Refer to the scald warnings and the section on scalding in Section V: Water Connections (page 15). It
is further recommended, in all cases, that the water temperature be set for the lowest temperature that satisfies your hot
water requirements for the installation. This will also provide the most energy efficient operation of the water heater and
minimizes scale formation.
Setting the water heater temperature at 120°F (49°C) will reduce the risk of scalds. Some states require setting lower
temperatures for specific installations.
The top immersion well of the single sensor control contains a redundant sensor for the high limit (energy cutoff). The high
limit circuit interrupts the main burner gas flow, should the water temperature exceed approximately 207°F (97.2°C). Error
code "80" will be shown on the water heater control display if the high limit temperature has been exceeded. Should the
high limit switch activate, it must be manually reset. This should only be done by a qualified service technician after the
cause of overheating has been corrected.
Contact your qualified installing contractor, service provider, or the manufacturer listed on the rating plate if continued high
limit operation occurs.
Service Panels
The service panels are located behind the service panel access covers, which are located around the exhaust elbow side
of the water heater. These panels contain a pressure switch that monitors the pressure in the exhaust pipe in case the
vent system becomes blocked. An exhaust high limit switch is used to monitor the ambient temperature of the exhaust
collector. This is a manually resettable switch. If this switch continues to trip, please contact an authorized service agency.
Latches
The latches allow easy access for servicing the water heater from the top. Open the three latches and lift the surround up
for servicing. No tools are required to obtain access to the top of the water heater. Replace the surround and re-latch
when the service has been completed.
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