Bradford White UPDX2-75T6FRN - Manual (Page 21)

UPDX SERVICE PROCEDURE IV
Blower Testing and Replacement
WARNING
115 volt potential exposure. Use caution when
making voltage checks to avoid personal injury.
Blower Testing
Is there 115VAC across
terminals shown in
photo 16?
Incorrect supply
voltage polarity.
Determine
power source
problem and
correct.
Does blower energize Within 2
minutes?
Y
Disconnect cord set
shown in photo 14 . Is
there 115VAC across
terminals shown in photo
15?
N
See pressure switch
testing
Page 19.
Is there 115 VAC at
wall outlet?
Check power cord
for damage.
Y
N
Disconnect
pressure switch
tubing from blower
(see photo 13).
Connect
manometer to
pressure tap of
blower
(see photo 13).
With blower running, and exhaust
adapter removed from top of blower,
is there a negative pressure of -2.30"
to -2.60" W.C.?
Step 1. Position gas control power
switch to the “ON”
position and adjust control
to call for heat.
Step 2. Remove the three screws
(Phillips Screw driver) from
control access cover on
blower assembly and
remove cover (see photos
10 and ll).
Reconnect cord set shown
in photo 14, is there
115VAC between blue wire
and green ground wire
(see photo 17)?
Replace blower.
Does cord set
have electrical
continuity?
Disconnect vent
system from top of
blower and remove
exhaust vent
adapter
(see photo 12).
Does blower energize after 2
minutes, run for 30 seconds
and shut down?
N
Is there 115VAC across blue
and green wires
(see photo 17)?
Blower OK.
Y
Repair or replace
power cord.
Replace blower.
Y
N
N
N
N
Y
Y
Y
Y
N
Pressure switch
tubing
Pressure Tap Remove Exhaust
Adapter
Shown with pressure
switch removed.
Green Ground
Wire
Blue Wire
Replace blower.
Y Determine voltage
problem and correct.
N
Page 21
11
13
14
15 16
17
12
Replace gas
control.
Y
Replace
cord set.
N
UPDX Series
Gas Control shown in
the “ON” Position
10
Control
Access
Cover
Screws
21