Watts AERCO Benchmark 2.0, User Manual

Page: 58 / 97

TROUBLESHO
OTING
8
-2
TABLE 8-1. BOIL
ER TROUBLESHOOTING
FAULT INDI
CATION
PROBABL
E CAU
SES
COR
R
ECTI
VE ACTI
O
N
AIRFLO
W FAULT
DU
RIN
G
IGN
ITION
1.
Blowe
r stop
ped run
ning d
ue
to thermal
or cu
rrent overloa
d
2.
Blocked Blo
w
er inlet or inl
et ductwo
rk
3.
Blocked ai
rflo
w switch
4.
Defe
ctive airflow switch
1.
Che
ck com
bu
stion blo
w
er
for sig
ns of ex
ce
ssive h
eat or high
curre
nt drain
that may trip therm
a
l or current overl
oad
device
s.
2.
Inspe
ct the in
let to the com
bustio
n blo
w
er
inclu
ding a
ny
duct
w
ork lea
ding up to the
combu
stion
blower for
sig
ns of
blocka
ge.
3.
Remove the
airflow
swit
ch
and inspe
ct for sig
ns of bl
ockag
e,
clea
n or repla
ce a
s ne
ce
ssary.
4.
Measure the airflow
swit
ch
for
continuity
with the com
bustio
n
blower runnin
g. If
there is a
n erratic re
si
stance readi
ng
or the
resi
stan
ce
re
ading i
s gre
ater than
zero ohms, repla
ce the swit
ch.
AIRFLO
W FAULT
DU
RIN
G
PU
RGE
1.
Blowe
r not ru
nning o
r ru
nni
ng too slo
w
2.
Defe
ctive Air Flow Swit
ch
3.
Blocked Air flow Switch
4.
Blocked Blo
w
er inlet or inl
et ductwo
rk.
5.
No voltage to
switch from control box.
1.
Start the unit. If
the blowe
r
doe
s not run
che
ck the blo
w
er
solid
state relay for input and out
put voltage. If the relay is o
kay,
che
ck the blo
w
er.
2.
Start the unit. If
the blowe
r
run
s, che
ck the airflo
w swi
tch for
contin
uity. Repla
ce the switch
if there is no contin
uity.
3.
Remove the
air flow switch and in
spe
ct
for sign
s of b
lockag
e,
clea
n or repla
ce a
s ne
ce
ssary.
4.
Inspe
ct the in
let to the com
bustio
n blo
w
er
inclu
ding a
ny
duct
w
ork lea
ding up to the
combu
stion
blower for
sig
ns of
blocka
ge.
5.
Measure for 24 VAC duri
ng start
seque
nce fro
m
ea
ch side of the
swit
ch to gro
und. If 24VAC is not p
resent refer to q
ualified
servi
ce pe
rso
nnel.
AIRFLO
W FAULT
D
U
R
ING RUN
1.
Blowe
r stop
ped run
ning d
ue
to thermal
or cu
rrent overloa
d
2.
Blocked Blo
w
er inlet or inl
et ductwo
rk
3.
Blocked ai
rflo
w switch
4.
Defe
ctive airflow switch
5. Combustion
oscillations
1.
Che
ck com
bu
stion blo
w
er
for sig
ns of ex
ce
ssive h
eat or high
curre
nt dra
w
that may trip therm
a
l or current overl
oad
device
s.
2.
Inspe
ct the in
let to the com
bustio
n blo
w
er
inclu
ding a
ny
duct
w
ork lea
ding up to the
combu
stion
blower for
sig
ns of
blocka
ge.
3.
Remove the
airflow
swit
ch
and inspe
ct for sig
ns of bl
ockag
e,
clea
n or repla
ce a
s ne
ce
ssary.
4.
Measure the airflow
swit
ch
for
continuity
with the com
bustio
n
blower runnin
g. If
there is a
n erratic re
si
stance readi
ng
or the
resi
stan
ce
re
ading i
s gre
ater than
zero ohms, repla
ce the swit
ch.
5.
Run u
nit to full fire. If
the unit rumble
s or runs
rou
gh, perfo
rm
co
mbus
tion calibration.