Bradford White U100L199E N Series, Service Manual

Page: 31 / 56

D oes in l et gas pressure
drop more than 2 " W . C .
during burner ignition ?
A d j ust gas
supp l y regu l ator
I nade q uate l y
si z ed regu l ator .
Y
N
N
Y
N
Y
N
V erify M inimum G as Supp l y Piping Re q uirements of :
M inimum ¾" N P T . (Schedu l e 4 0 b l ac k I ron Pipe
recommended) .
Reconfigure gas
supp l y piping
Y
O bser v e burner operation through the sight glass located on the combustion insert mounting flange. N ormal burner operation
should ignite smoothl y , without e v idence of coughing or huffing upon ignition. T he burner flame should be a blue flame near the
burner surface in a uniform flame pattern. O ccasional y ellow or white strea k s are normal.
I nlet gas
pressure tap
V enturi
ad j ustment
D oes main burner
L ight ?
Remove high vo l tage wire connected at the
spar k rod and ho l d appro x imate l y ¼" from meta l
ground with insu l ated p l iers during the ignition
cyc l e (3 second spar k tria l period) .
I s there spar k to ground ?
Y
N
Chec k spar k gap to burner
(see “Spar k Rod G ap
I nspection”)
Chec k resistance of high vo l tage
cab l e . Resistance shou l d be 0 - 1 ohms .
I f resistance is high, rep l ace spar k
cab l e . I f spar k cab l e is good, rep l ace
Contro l B oard .
N
Y
Can Spar k ing be seen /
heard at the spar k rod
to the burner ?
Proceed to ne x t page
W ith manometer, chec k in l et
gas pressure . I s it stab l e
between 7 " & 1 4" W . C . static ?
(heater not running)
(see i ll ustrations at right)
I s gas supp l y pressure
regu l ator ad j ustab l e to
maintain proper and
stab l e setting ?
Y
N
W A R NIN G
120 vo l t potentia l
exposure . Use caution
making vo l tage checks to
avoid persona l injury .
W A R NIN G
Removing screw from
in l et gas pressure tap wi ll
immediate l y a ll ow gas to
f l ow from pressure tap .
N ote: Mode l s using meta l fiber mesh burner a red g l ow from the
burner surface is norma l.
3 1
Chec k continuity of
spar k rod . I s
reading 0 - 1 Ohm ?
Y
N
Rep l ace Spar k Rod
(see “Spar k Rod
G ap I nspection and
Rep l acement”
C HE C K S P A R K RO D
R E S I S T A N C E
M eter probe
M eter probe
S par k R od
V olt meter set to
O HM setting
V oltmeter set to
O HM setting
S par k R od
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