Safety Circuit Voltage Trace - Bradford White LC2PV50H76N Service Manual

Condensing PV Series

Safety Circuit Voltage Trace

NOTE: This procedure assumes a cool tank.
Remove three screws (Phillips Screw driver)
from the control access cover on the blower
and remove the cover (see photo 17).
115 volt potential exposure. Use
caution to avoid personal injury.
Position the gas control switch to the "ON"
position and adjust the thermostat dial to call for
heat. Is there 10 to 13 VAC between the
temperature switch terminal and the green ground
screw? The blower must be running during this
voltage check. (see photo 18)
Y
Is there 10 to 13 VAC between the
pressure switch terminal and the green
ground screw?
(see photo 18)
Y
Do you hear or can you
see the ignitor sparking?
Y
Safety circuit voltage is OK.
If burner does not light, observe the
LED flash code on the gas control
and refer to the troubleshooting
section(see page 14).
30
30
WARNING
N
N
Correct ignitor/sensor problem.
Check ignitor/sensor
N
(see page 18).
Is the ignitor/sensor OK?
18
Is the LED on the gas control
Y
flashing a "heartbeat" code
(alternating bright/dim)?
N
Verify 115VAC to
the gas control
(see page 31)
N
Y
Pressure Switch
Terminals
Ground Screw
17
No voltage from gas control.
Call for technical support.
Check for loose or broken wire
connection at switch terminals.
Y
Is there continuity through the
blower temperature switch
(see page 23)?
N
Determine cause of blower
temperature switch activation
and correct(see page 24).
Faulty cord set or gas control.
Temperature
Switch Terminals