Combustion System Testing And Replacement - Bradford White EF100T150(E)*(N Service Manual

Observe burner operation through the sight glass located on the combustion insert mounting flange. Normal burner
operation should ignite smoothly, without evidence of coughing or huffing upon ignition. The burner flame should be a blue
flame near the burner surface in a uniform flame pattern. Occasional yellow or white streaks are normal.
For models with Hot Surface Ignition System
Note: On higher input models using metal fiber mesh burner (serial
number "CK" and later) a red glow from the burner surface is normal.
Verify Minimum Gas Supply Piping Requirements of:
Minimum 1" NPT for EF100T399, all others use ¾"
NPT. (Schedule 40 black Iron Pipe recommended).
Y
With manometer, check inlet
gas pressure. Is it stable
between 7" & 14" W.C. static?
(heater not running)
(see illustrations at right)
Y
Does inlet gas pressure
drop more than 2" W.C.
during burner ignition?
N
WARNING
120 volt potential
exposure. Use caution
making voltage checks to
avoid personal injury.
Do you see the igniter
N
glowing through burner
site glass during the
warm up period?
Y
Is igniter resistance
less than 150 Ohms
N
(cold)?
(see check igniter
illustration)
Y
Proceed to next page
N
Inadequately
sized regulator.
N
Is gas supply pressure
N
regulator adjustable to
Y
maintain proper and
stable setting?
Y
Replace ignition module.
(see "Ignition Module
Replacement Procedure")
Refer to ignition module illustration below,
is there 120VAC across terminals
P6(1) and P6(2)?
(Note: Igniter LED must be lit during this check).
Y
Replace
hot surface igniter.
(see "Hot Surface Igniter
Replacement Procedure)
Reconfigure gas
supply piping
Adjust gas
supply regulator
WARNING
Removing screw from
inlet gas pressure tap will
immediately allow gas to
flow from pressure tap.
N
Volt meter set to
OHM setting
Venturi
adjustment
Inlet gas
pressure tap
IGNITION MODULE
Meter probe
Hot surface
igniter
CHECK IGNITER
RESISTANCE
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