47
SERVICING
Sy
mp
toms of
Ab
normal Operation
(Lega
cy
&
ComfortNet™ Thermostat
)
7-Segment LED
Codes
Characters Will Alternate
Fault Description
ComfortNet™
Thermostat Onl
y
Possible Cause
s
Corrective
A
ction
s
Notes & Caution
s
Message
Code
L
ED displa
y
is ON continuously
ON
N
ormal operation
None
N
one
Normal operation
N
one
N
ormal operation
E
lectric heaters fail to energize on a
call for W1 or Aux
iliary
/Emergenc
y
heat
Integrated control module LED
displ
ay
prov
ides the indicated error code.
ComfortNet™ thermostat “Call for
Serv
ice” icon illuminated
ComfortNet™ thermostat scrolls
“Check Air Handler” message
EC
H
eater kit selected v
ia
dipsw
itches is too
large for heater kits
specified in shared
data
s
et
HTR TOO
LARGE
EC
Heater kit selected v
ia
dips
wi
tches is too large for
heater kits in shared data set
V
erif
y
electric heat dipsw
itch
settings
V
erif
y
the installed electric
heater is v
alid for the air
handler blow
er. Check
nameplate or Specification Sheet applicable to y
our
model* for allow
able heater
kit
(s
).
Verify
sha
red
data set is
correct for the specific model. Re-populate data using
correct memory
car
d if
required.
Turn po
we
r OFF prior to
repair. Use memor
y
card for
the specific model.
I
nsert memor
y
card
BEFORE turning pow
er
ON. Memory
card
may
be remov
ed after data is
loaded. Turn pow
er off before
remov
ing memory
card.
E
lectric heat airflo
w
is higher than
ex
pected on a call for W1 or
Aux
iliary
/Emergenc
y
heat
I
ntegrated control module LED
display
prov
ides the indicated error code.
EC
Heater kit selected v
ia
dipsw
itches is too
small for heater kits specified in shared data
s
et
HTR TOO SM
ALL
EC
Heater kit selected v
ia
dipsw
itches is too small for
heater kits in shared data set
Verify
electric heat dipsw
itch
settings
Verify
the installed electric
heater is v
alid for the air
handler blo
we
r. Check
nameplate or Specification
Sheet applicable to y
our
model* for allow
able heater
kit
(s
).
Verify
sha
red
data set is
correct for the specific model.
Re-populate data using
correct memory
car
d if
required.
Turn po
we
r OFF prior to
repair. Use memor
y
card for
the specific model.
Insert memory
card
BEFORE turning po
we
r
ON. Memor
y
card
may
be remov
ed after data is
loaded. T
urn pow
er off before
remov
ing memory
card.
E
lectric heat airflo
w
is higher than
ex
pected on a call for W1 or
Au
xi
liary
/Emergenc
y
heat
I
ntegrated control module LED
displ
ay
prov
ides the indicated error code.
EC
Heater kit selected v
ia
dipsw
itches does not
heater kits specified in
shared data set
NO HTR
MA
TCH
EC
Heater kit selected v
ia
dipsw
itches is doesn’t match
heater kits in shared data set
Verif
y
electric heat dips
wi
tch
settings
Verif
y
the installed electric
heater is v
alid for the air
handler blow
er. Check
nameplate or Specification Sheet applicable to y
our
model* for allo
wa
ble heater
kit(
s)
.
Verify
sha
red
data set is
correct for the specific model. Re-populate data using correct memory
car
d if
required.
T
urn pow
er OFF prior to
repair. Use memory
card for
the specific model.
Insert memory
card
BEFORE turning pow
er
ON. Memory
card
may
be remov
ed after data is
loaded. Turn po
we
r off before
remov
ing memory
card.
Integrated control module LED
displa
y
EF error code. ComfortNet™ thermostat “Call for
Serv
ice”.
EF
A
ux
s
wi
tch open
Au
x
Alarm
Fault
EF
H
igh w
ater lev
el in the
ev
aporation coil.
Check ov
erflo
w
pan and
serv
ice
Turn po
we
r OFF prior to
serv
ice.
PCBJA104 AIR HANDLER DIAGNOSTIC CODES
