Watts AERCO Benchmark 2.0, User Manual

Page: 60 / 97

TROUBLESHO
OTING
8
-4
TABLE 8-1. BOILER TRO
UBLESHOOTING – Contin
ued
FAULT INDI
CATION
PROBABL
E CAU
SES
CORRECTI
VE ACTI
O
N
FLAME LOS
S
D
U
R
ING RUN
1.
Wo
rn Flame
Dete
ctor o
r cracked
cer
ami
c.
2. Defective
Differential
Regulator.
3.
Poor combu
stion calib
ratio
n.
4.
Deb
ris o
n bu
rner.
5.
Blocked cond
ensate drai
n.
1.
Remove a
nd
insp
ect the Fl
ame Dete
cto
r for sign
s of wea
r or
cra
cked
ce
ra
mic. Repl
ace if nece
ssary.
2.
Che
ck ga
s pressure re
adin
gs u
sing a g
auge or m
ano
meter into
and out of the
Air/Fuel Valve to ensu
re th
at the gas p
re
ssure
into and out o
f the valve is
corre
ct.
3.
Che
ck com
bu
stion calibration. Adjust as
necessa
ry.
4.
Remove the
burn
er a
nd in
spe
ct for any
carbon o
r de
bris. Cl
ean
and rei
nstall.
5.
Remove bl
ockag
e in co
nd
ensate drai
n.
HEAT DEMA
ND
FAILURE
1.
The He
at De
mand Relays
on the
Ignition/Stepp
er boa
rd faile
d to
ac
tivate when c
ommanded
2.
Relay is a
ctivated wh
en no
t in
Dema
nd
1.
Press CLEAR button an
d resta
rt
the uni
t.
If the fault
persist
s,
repla
ce Igniti
on/Steppe
r (IGST) Boa
rd.
2.
Defe
ctive rela
y. Replace IGST Board.
HIGH EXHA
U
ST
TEMPERATURE
1.
Defe
ctive exhaust sen
sor.
2.
Carbon
ed he
at exchan
ger
due to
inco
rrect com
bustio
n cali
bration
1.
Measure the actual exh
au
st te
mperature and continu
ity of
the
exhau
st sen
sor. If the exh
aust tempe
rat
ure is le
ss than 475
o
F
and the exha
ust se
nsor
sh
ows co
ntinuit
y replace the sen
so
r.
2.
If exhaust temperature i
s greate
r than
500
o
F,
che
ck
comb
ustio
n calibratio
n. Cal
ibrate o
r rep
ai
r as ne
ce
ssa
ry.
HIGH GAS
PRESSURE
1.
Incorre
ct su
pp
ly gas pressure.
2.
Defe
ctive Supply Reg
ulato
r or
Wrong Style Reg
ulator
3.
Defe
ctive Hig
h Gas Pressu
re Switch
1.
If using a non
-lock up
style regul
ator for t
he ga
s su
ppl
y,
measure stati
c ga
s pre
ssu
re dow
nstrea
m, it should b
e 14”WC
or less. Adju
st as necessa
ry.
2.
If gas sup
ply pre
ssure ca
nnot be lowere
d, a lock-up
style
regul
ator may
be requi
re
d or the supply regul
ator may
be
defective.
3.
Remove the l
ead
s from the
high ga
s pre
ssure
swit
ch.
Measure
contin
uity across the co
m
m
on and n
ormally closed termin
als
with the unit not firing. Re
place the switch if it does n
ot sho
w
contin
uity.