49
SERVICING
ComfortNet™
Thermostat Onl
y
Sy
mp
toms of
A
bnormal Operation
(Legac
y
& ComfortNet™ Thermostat)
7-Segment LED
Codes
Characters Will Alternate
Fault Description
Message
Code
Possible Causes
Corrective
A
ctions
Notes & Cautions
Air handler blo
we
r fails to operate.
Integrated control module LED
display
prov
ides indicated error code.
C
omfortNet™ thermostat “Call for
Ser
vi
ce” icon illuminated.
C
omfortNet™ thermostat scrolls
“Check Air Handler” message.
b0
Circulator blow
er
motor is not running
w
hen it should be
running.
MO
TOR
NOT RUN
b0
L
oose w
iring connection at
circulator motor pow
er leads
or circulator motor pow
er
leads disconnected.
Failed circulator blo
we
r motor.
Tighten or correct
wi
ring
connection. C
heck circulator blow
er
motor. Replace if necessar
y.
Turn pow
er OFF prior to
repair Replace circulator motor wi
th correct
replacement part.
A
ir handler blo
we
r fails to operate.
Integrated control module LED
display
prov
ides indicated error code.
C
omfortNet™ thermostat “Call for
Ser
vi
ce” icon illuminated.
C
omfortNet™ thermostat scrolls
“Check Air Handler” message.
b1
Integrated control
module has lost communications w
ith
circulator blow
er
motor.
MO
TOR
COM
M
b1
L
oose w
iring connection at
circulator motor control leads.
Failed circulator blo
we
r motor.
Failed integrated control module.
Tighten or correct w
iring
connection. C
heck circulator blo
we
r
motor. Replace if necessary
.
C
heck integrated control
module. Replace if nece
ssa
ry
.
Turn pow
er OFF prior to
repair Replace circulator motor wi
th correct
replacement part. Replace integrated control module w
ith
correct replacement
part.
A
ir handler blo
we
r fails to operate.
Integrated control module LED
display
prov
ides indicated error code.
C
omfortNet™ thermostat “Call for
Ser
vi
ce” icon illuminated.
C
omfortNet™ thermostat scrolls
“Check Air Handler” message.
b2
Circulator blow
er
motor horse pow
er in
shared data set does
not match circulator
blo
we
r motor horse
po
we
r.
MO
TOR
MI
SM
ATCH
b2
Incorrect circulator blow
er
motor in air handler blo
we
r.
Incorrect shared data set in
integrated control module.
V
erif
y
circulator blo
we
r motor
horse po
we
r is the same
specified for the specific air
handler blo
we
r model.
Replace is necessary
.
V
erif
y
shared data set is
correct for the specific model. Re-populate data using
correct memory
car
d if
required.
Turn pow
er OFF prior to
repair R
eplace motor
wi
th
correct replacement
part. Use memor
y
card for
the specific model Insert memor
y
card
BEFORE turning pow
er
ON. Memory card may
be remo
ve
d after data is
loaded. E
rror code
wi
ll be
cleared once shared
data and motor horse po
we
r match.
Turn po
we
r off before
remov
ing memory
card
A
ir handler blo
we
r operates at reduced
performance.
A
irflo
w
deliv
ered is less than ex
pected.
Integrated control module LED
display
prov
ides b3 error code.
b3
Circulator blow
er
motor is operating in a
pow
er, temperature, or
speed limiting condition.
MO
TOR
LIM
ITS
b3
B
locked filters.
R
estrictiv
e ductw
ork.
U
ndersized duct
wo
rk.
H
igh ambient temperatures.
C
heck filters for blockage.
Clean filters or re
mo
ve
obstruction.
Check ductw
ork for blockage.
Remo
ve
obstru
ctio
n. Verif
y
all registers are fully
open.
Verif
y
duct
wo
rk is
appropriately
si
zed for
sy
stem. R
es
iz
e/r
ep
lace
duct
wo
rk if necessar
y.
See "Installation Instructions" for installation requirements.
Turn pow
er OFF prior to
repair.
A
ir handler blo
we
r fails to operate.
Integrated control module LED
display
prov
ides indicated error code.
C
omfortNet™ thermostat “Call for
Ser
vi
ce” icon illuminated.
C
omfortNet™ thermostat scrolls
“Check Air Handler” message.
b4
Circulator blow
er
mo
tor se
ns
es
a
los
s
rotor control. Circulator blow
er
motor senses high current.
MO
TOR
TRIPS
b4
A
bnormal motor loading,
sudden change in speed or torque, sudden blockage of air handler blow
er/coil air inlet or
outlet.
H
igh loading conditions,
blocked filters, v
ery restrictiv
e
duct
wo
rk, blockage of air
handler blow
er/coil air inlet or
outlet.
Check filters, filter grills/registers, duct sy
stem
,
and air handler blow
er/coil air
inlet/outlet for blockages.
Turn pow
er OFF prior to
repair.
PCBJA104 AIR HANDLER DIAGNOSTIC CODES