L.B. White Guardian with Smart Sense / Direct Connect - Spark Ignition (250K) - Manual (Page 22)

21
Problem LED constant on Red LED not on during a call for heat. Heater does not operate.
Normal Operation
Is heat
er
connect
ed t
o
its
po
w
er supply?
Connect it t
o
the
po
w
er supply
.
Ye
s
No
Ye
s
Is
pr
oper
v
oltage supplied
to
heat
er po
w
er cor
d
and thr
ough
po
w
er cor
d?
Check dataplat
e f
or electrical supply
req
uirements. Pr
o
vide pr
oper
v
oltage. Check cir
cuit break
er
s.
Check po
w
er cor
d f
or continuity
.
Are 2
4
v
olts
supplied fr
om
transf
ormer?
R
eplace 40 V
A
transf
ormer
No
No
No
Ye
s
Are
2
4
v
olts supplied
to
ignition
module?
P
oor electrical connection or br
ok
en wire present.
R
epair or replace.
Ye
s
R
eplace ignition module.
Is
pr
oper
v
oltage supplied
to
40 V
A
transf
ormer?
Check electrical connections and
po
w
er supply t
o
transf
ormer
.
R
epair as necessar
y.
No
Ye
s
Ye
s
Is
building contr
oller
calling f
or heat?
Set contr
oller t
o
call f
or heat.
No
Heater does not cycle above minimum heat output.
Is building
contr
oller
calling f
o
r
heat?
No
Is pr
oper gas
pressure supplied
to
heat
er?
Ye
s
Pr
o
vide pr
oper
pressure t
o
heat
er and
check with a gauge.
No
Set the building
contr
oller t
o
call f
o
r
heat.
Is v
ariable rat
e
solenoid on gas
contr
ol v
alv
e receiving
DC v
olts ?
No
Ye
s
Problem
Measure acr
oss t
erminals of modulating gas
contr
ol v
alv
e f
or an
ywhere fr
om 1-1
5 v
olts DC.
If absent, check all wiring and building
contr
oller settings. If wiring and settings are
good, replace the signal conditioner
.
Def
ectiv
e v
ariable
rat
e gas contr
ol
solenoid. R
eplace
gas contr
ol.
Ye
s
Is the 20 V
A
transf
ormer
recie
ving 1
1
5 v
olts
and supplying 2
4
v
olts t
o
signal
conditioner?
No
Check electrical connections
and po
w
er supply t
o
transf
ormer
.
If no po
w
er fr
om transf
ormer t
o
conditioner
, replace the
transf
ormer
.
Ye
s
LED Flashing One Time Air proving switch contacts are closed before fan motor is started. Fan motor does not run. Heater does not light.
Is air
-
pr
o
ving switch
shor
ted? (P
er
form
continuity check on air
-
pr
o
ving switch.)
Ye
s
No
Ye
s
R
eplace air
-pr
o
ving
switch
Is air
-pr
o
ving switch
arm or paddle binding on housing? Is there
an obstruction in
heat
er outlet?
R
epair and/or remo
v
e
obstructions. check for damaged f
a
n
housing. Clean or repair as needed.