U
PDX
SE
RV
I
C
E
PR
O
C
E
D
U
R
E
VI
Gas Control/Thermal Well Testing and
R
eplacement
U
PD
X
Se
r
ie
s
Thermal Well Testing
Thermal
w
ell testing
P
osition gas control po
w
er s
w
itch to
the
“
O
FF”
position
and
dis
c
onne
c
t
thermal
w
ell harness
f
rom gas
control.
N
Y
Using a multi
-
meter set to the ohms setting, insert one meter probe (see caution)
into center wire position of thermal well connector, insert the second probe (see
caution) into either of the outside wire positions (see photo 20)
.
Alternate the probe on the outside position to the opposite outside wire position
(see photo 21)
.
Replace
thermal
well
(see
pa
g
e
2
7).
U
sing a m
u
lti-meter set to the
O
hms setting
,
determine the
resistance o
f
thermal
w
ell sensor
(
see ca
u
tion photos
25 & 26)
.
Disconnect
Thermal
Well
Wire
Harness
25
2
6
Replace
g
as
control
(see
pa
g
e
2
7
or
2
9).
P
a
g
e
25
Gas Control Testing
This section is for models with serial
N
umbers
starting
with
“K”
or
earlier
.
See page 34 for gas control input &
output testing
.
O
nce the thermal
w
ell resistance
v
al
u
es are
k
no
w
n
,
the
w
ater
temperat
u
re m
u
st also
b
e
k
no
w
n to determine i
f
the resistance
v
al
u
es are correct.
S
ee page
26
to o
b
tain
w
ater temperat
u
re.
A
re thermal
w
ell resistance
v
al
u
es correct?
CA
UT
I
O
N
D
O
N
O
T
u
se
stan
d
ar
d
m
u
ltimeter
pro
b
es
f
or
this
test.
Doin
g
so
will
d
ama
g
e
connector.
U
se
special
pin
t
y
pe
electronic
pro
b
es
or
small
d
iameter
wire
pins
inserte
d
into
connector.
I
f
Control
has
g
one
into
TC
O
locko
u
t
du
e
to
excessive
tank
temperat
u
re
(
f
o
u
r
f
lash,
3
secon
d
pa
u
se)
reset
control
b
y
rotatin
g
kno
b
o
f
temperat
u
re
control
to
the
minim
u
m
settin
g
f
or
at
least
6
secon
d
s
b
e
f
ore
ret
u
rnin
g
to
d
esire
d
temperat
u
re
settin
g
.
O
b
serve
heater
operation.
I
f
control
contin
u
es
to
locko
u
t
du
e
to
excessive
tank
temperat
u
re,
procee
d
to
thermal
well
testin
g
to
d
etermine
ca
u
se.
Gas
Control
shown
in
the
“
O
FF”
P
osition
25
Содержание UPDX series
Страница 44: ......
