PDX 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 17 ?
Incorrect supply
voltage polarity
Determine
power source
problem and
correct.
Does blower energiz e
Within 2 minutes?
Y
Disconnect cord set
shown inphoto 9. Is
there 115VAC acros s
terminals shown in
photo 16
N
See pressure
switch testing
Page 17& 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 therea negative
pressure of -2.30" to -2.60" W.C.?

Step 1. Position gas control power switch

to “ON” position and adjust control to call forheat.

Step 2. Remove the three screws ( Phillips Screw driver)

from control acce ss cover on blower assem bly and

remove cover (see photo 12).

Reconnect cord set
shown in photo 9, i s
there 115VAC between
blue wire and green
ground wire
(see photo 18)
Replace blower
Does cord set
have electrical
continuity?
Disconnect vent
system from top of
blower and remove
exhaust vent
adapter.
(see photo 15)
Does blower energiz e after
2 minutes, run for 30
seconds and shut down?
N
Is there 115vac ac ross
blue and green wires
(see photo 18)
Blower OK
Y
Repair orreplace
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
12
13
14
16 17
18
15
Replace
gas control
Y
Replace
cord set
N
PDX Series
21