Blower Testing And Replacement - Bradford White PDX Series Service Manual

PDX Series
Blower Testing
Step 1. Position gas control power switch
to "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 photo 8).
Does blower energize Within 2
minutes?
N
9
Does blower energize after 2
minutes, run for 30 seconds
and shut down?
N
Disconnect cord set
shown in photo 9. Is
there 115VAC across
terminals shown in photo
12
N
Is there 115 VAC at
wall outlet?
Y
Check power cord
for damage.
N
Replace blower
20
Disconnect
pressure switch
Y
tubing from blower.
(see photo 13)
10
Pressure tap
Pressure switch
tubing
See pressure switch
Y
testing
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Is there 115VAC across
Y
terminals shown in
photo 13 ?
N
Incorrect supply
voltage polarity
Determine
Replace
N
power source
cord set
problem and
correct.
Repair or replace
Y
power cord
PDX SERVICE PROCEDURE IV

Blower Testing and Replacement

WARNING
115 volt potential exposure. Use caution when
making voltage checks to avoid personal injury.
8
Disconnect vent
Connect
system from top of
manometer to
blower and remove
pressure tap of
exhaust vent
blower.
(see photo 11)
(see photo 15)
With blower running, and exhaust
adapter removed from top of blower,
is there a negative pressure of -2.30"
Is there 115vac across blue
N
Determine voltage
problem and correct.
12
Y
Reconnect cord set shown
in photo 8, is there
115VAC between blue wire
and green ground wire
(see photo 14)
N
Does cord set
N
have electrical
continuity?
Y
Replace gas
control
adapter.
Remove exhaust
adapter
Y
to -2.60" W.C.?
N
Y
and green wires Replace blower
(see photo 14)
13
Y
Replace blower
Green ground
wire
Shown with pressure
switch removed.
11
Blower OK
14
Blue wire
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