Bradford White U-TW4-75S-76R-3N - Manual (Page 41)

Page 41
115 VAC Circuit Trace
WARNING
115 volt potential exposure. Use caution making voltage checks to avoid
personal injury.
LED status:
None, control
LED not on or
flashing.
LED status:
Short flash
once every four
seconds.
LED status:
“Heartbeat”,
alternates
bright/dim.
LED status:
Various flash-
ing error codes.
Waiting for call
for heat.
Thermostat call-
ing for heat.
Verify error
code as listed
on page 17. Disconnect cord
set as shown in
photo 9.
Using a volt meter
set to volts AC, is
there 115VAC across
terminals shown in
photo 10?
Check for damage
to AC supply
power cord.
Repair damage.
Replace blower.
Is there 115VAC
across terminals
shown in photo 11?
Incorrect supply
voltage polarity.
Reconnect cord set
shown in photo 9.
Disconnect wire har-
ness from gas control
(see photo 12).
Locate black & white wires at connector, it
may be necessary to pull back wire sheath to
identify wire colors (see photo 13).
Is there 115VAC across
black & white wire as
shown in photo 13?
Call for technical support.
Replace gas control.
N
N
N
Y
N
Y
N
Y
Wire harness
Check for 115VAC between black and white wires.
-NOTE-
Electronic meter probes required. Use car not to
damage connector during this check.
Wire sheath pulled back to
identify wire colors
9 11
12
13
10
41