Bradford White EF-100T-399-3X - Manual (Page 18)

System Observation
For models with Direct Spark Ignition
Water Heater Fault: Water heater does not operate
Display Error Code: Water heater display does not operate - blank display
Check main power supply to water
heater - fuse, circuit breaker, plug
receptacle, line cord or wiring to water
heater.
Check to make sure switch on front of
control panel is in the ON position
Verify Primary voltage at the
control board.
Verify Secondary voltage at the control
board.
Check wires for proper termination
to control display.
Are wire terminations connected
properly to control display?
N
Y
CAUTION
Use caution not to damage connectors when
making voltage measurements or jumping terminals
WARNING
120 volt potential exposure. Use caution
making voltage checks to avoid personal injury.
Is 24VAC present between
RED and BLACK wire pin
connections on the back of
Control Display?
1 2 3
8
6
5
4 3
1
1 2
1
4
1
3
3
2
1
1
5
3
P2 P4 P5 P7 P3
CONTROL BOARD
P10 P9 J1
Refer to Control Board illustration.
Voltage at primary pins P2(1) & P2(3)
will be 110-120. If not, check Line In
pins P3(1) & P3(4). Check line cord with
volt meter. Replace line cord if
defective.
Refer to Control Board illustration. Voltage at
secondary pins P4(1) & P4(2) will be 24VAC.
If not, check transformer. Replace
transformer or wire harness.
Does water heater display operate?
Does the combustion blower start to
operate? Increase thermostat setting if
tank is warm.
Is 24VAC present between E-COM
screw terminals P9(2) & P9(3) on
the Control Board.
Y
N
Replace Control
Display.
N
Display Operates - See next
page
Transformer
Top terminals are 24VAC;
Bottom terminals are 120VAC
18
Y
Make proper wire
terminations
N
Replace
Control Board
Y
Check wire
harness for
proper continuity
18