Form 43471000
Sept 2011
-29-
20.0)
TROUBLESHOOTING GUIDE
T
urn on line volt
age
and thermost
at. Does
the green monitoring light come on?
Y
es
No
Is there 120V between the L1 and L2 terminals on the terminal block in the control cabinet?
Y
es
No
Are the black lead wires of the green light securely on the terminals?
No
Y
es
Replace the green light.
Rep
air connection.
Check line volt
age at
thermost
at and line
volt
age curcuit. Rep
air
fault.
Is the draf
t inducer
on?
Y
es
No
Are the black and white lead wires of the draf
t inducer securely
on the terminals L1 and L2?
No
Y
es
Rep
air connection.
Is 120V on the terminal of the black lead wire of the draf
t
inducer motor?
Does the red monitoring light come on?
Y
es
No
Is there 24 vac between terminals of the transformer on the secondary side?
Y
es
No
Check the terminal block for continuity; replace it if no continuity
.
Rep
air connections.
Is the air hose securely connected to the air switch and the air sensing tubing at the blower?
No
Clean out hose and probe.
T
roubleshooting
continued on the next page.
No
Y
es
Check terminal block for continuity
. Replace
it if no continuity
.
Disconnect the power and check motor lead wires.
Any wire
broken?
Y
es
No
Rep
air broken wires.
Check the blower wheel. Does it turn freely?
Y
es
Replace motor
Check blower wheel. Is there any damage?
Replace blower wheel.
Readjust blower wheel on shaf
t &
retighten set crew
.
Check the air sensing tube and hose.
Are
they clear and unobstructed?
Check the pressure at the air switch. Is it higher than the minimum required?
Is the red wire from transformer securely connected to air switch terminal C?
Move the red wire to air switch terminal C.
Replace the red monitoring light.
Is one wire of the red light connected to air switch terminal NO?
No
Y
es
Replace transformer
.
Are the black and white wires to the transformer securely on the terminals?
No
Y
es
Rep
air connection.
No
No
Y
es
No
No
Check the volt
age
between air switch terminal C and ground, is it 24 vac?
Y
es
Is there120 vac on the primary side of the transformer?
Y
es
No
When the blower is running, is there 24 vac between air switch terminal NO and ground ?
No
Move the wire to air switch terminal NO.
Is the other wire of the red light connected to the terminal common of transformer?
No
Y
es
Connect this wire of the red light to the transformer terminal along with the white wire from ignition module.
Y
es
Y
es
No
Y
es
Y
es
Check the red wire from transformer for continuity
.
Replace it if no continuity
.
Y
es
Replace the air switch.
No
Check the air int
ake
and vent.
Are there
any blockages?
Y
es
No
Remove blockage. Rest
art
troubleshooting.
Check vent and fresh air lengths.
Are they
within the maximum permissible?
No
Y
es
Reduce them within the maximum permissible.
Remove the blower
.
Is the wheel free from dirt and dust?
Clean the blower wheel. Rest
art
troubleshooting.
No
Y
es
Does the blower turn freely?
No
Y
es
Replace the blower assembly
.
Check the restrictor plate st
amped ID. Is
it correct for the heater?
No
Y
es
Replace the restrictor plate.
Cont
act factory for
assist
ance.
