Carrier 58MTB - Manual (Page 17)

17
Is LED status light on? Is LED status light b
linking rapidly
without a pause? Is LED status light b
linking ON/OFF slo
wly
with a combination of shor
t and
long flashes?
Deter
mine status code
.
The status code is a
2 digit number with the first digit deter
mined
by
the number
of shor
t flashes and the
second
digit b
y the number of long flashes?
Go to section belo
w f
or the status code that
w
as flashed.
Is there 115V at L1 and L2? Is there 24V at SEC
-1 and SEC
-2?
Replace fur
nace control.
Chec
k f
or correct
line v
oltage polar
ity and
grounding. If units are twinned, check for proper low-voltage (24V) transformer phasing. To
recall status code br
iefly remo
ve and reconnect one RED wire from the
limit s
witch
or flame rollout s
witch to displa
y stored status code
. On RED LED
control do not remo
ve po
wer or b
lo
wer access panel bef
ore initiating status
code recall.
Y
ou can also recall the pre
vious status code b
y momentar
ily
shor
ting the
TEST/TWIN ter
minal to Com24V ter
minal until
the LED goes out.
LED will flash the status of the pre
vious code or status code #11 (1 shor
t and
1 long flash) if there w
as no pre
vious code
. After the control repeats the code
4 times
, the control will star
t the component test sequence
. Once initiated
the control will tu
rn
ON at HI HEA
T speed.
The inducer will r
un f
or the entire
component
test.
The HSI, b
lo
w
er motor L
O
HEA
T speed, H
I HEA
T speed, and
COOL speed will r
un
fo
r 10 – 15 seconds each.
Gas
va
lv
e and humidifier will
not be tur
ned on.
When the b
lo
wer motor is tur
ned OFF the inducer wi
ll be
sw
itched to lo
w-speed f
or 10 seconds
.
W
as
there a pre
vious status
code
other
than #11?
Is door s
witch closed?
Is there 115V going to s
witch?
Replace door s
witch.
Replace tra
nsf
or
mer
.
Does the control respond to
W/W1,
W2, Y1,
Y/Y2, and G (24V) ther
mostat signals?
Run system t
hrough a lo
w-heat, high-heat,
or cooling cycle to chec
k operation.
Status
codes are erased after 72 hours
. On RED
LED
boards stored status codes can also
be
erased whene
ve
r (115V or 24V)
is interr
upted.
Replace fur
nace control.
Close door s
witch and go bac
k to ST
A
R
T.
Is circuit break
er closed?
Chec
k f
or continuity in wire from circuit
break
er to fur
nace
.
Close circuit break
er and go bac
k to ST
AR
T.
Chec
k room ther
mostat or
interconnecting cab
le
.
Is 24V present at
W/W1,
W2,
Y1,
Y/Y2 or G
ther
mostat ter
m
inals on the fur
nace
control?
Disconnect all
the ther
mostat wires f
rom
the
fur
nace control.
Does the prob
lem repeat when using a
jumper wire? The ther
mostat is not compatib
le with the
fur
nace control.
Either in
stall
a
ballast
resistor
,
connect the Com24V ther
mostat ter
minal to
the ther
mostat, or replace the ther
mostat.
NO YES YES
NO YES YES
YES YES
YES YES
YES
NO NO
NO NO
YES
NO
NO
NO
YES
YES
NO NO
ST
AR
T
NO
TR
OUBLESHOO
TING GUIDE —
TW
O
-ST
A
G
E
A05111
A05095
58MTB