5-4
Troubleshooting
Section 5
Zo
ne
te
mp
dis
plays
‘++
+’?
Re
place
I/O bo
ard
The
rmo
co
uple
short error.
Re
plac
e the
heater
Y
IO bo
ar
d
the
rm
ist
or
wor
king?
N
Bad he
ate
r.
Re
place heater
Re
sistance
value
of heater
good?
N
N
Y
Y
Go to Zone
Diagnostics page
and note the
ac
tua
l
tem
p f
or
the
zo
ne
Zo
ne
e
rr
or
:
Te
mper
atu
re too
lo
w
M
ult
ip
le
zones
displa
y
‘+
++
’?
N
Y
Ther
mo
coupl
e s
hort
erro
r. Unplug e
ach
th
er
m
oc
ou
pl
e c
on
ne
ct
ed
to the I/
O boar
d one
at
a
tim
e. If issue
go
es aw
ay
,
no
te
the heater positio
n
an
d r
ep
la
ce
th
e h
ea
ter
.
Ve
ri
fy
2
zones
display ‘+++’
Y
Measured temp –
actual shelf
te
mp
>3
5F
?
Remo
ve s
helf and
press agai
ns
t the
th
er
mo
coupl
e
an
d re
‐
instal
l the
sh
el
f
Measure the shel
f
te
mp
er
at
ur
e o
f t
he
heat
er wi
th an external
tem
peratur
e sen
sor
Re
sistance
value of he
ater
good?
Re
plac
e t
he
he
at
er
N
Y
N
Y
FAS ONLY!
Temperature Too Low/Shelf Temp Low Issues Troubleshooting
