Service Manual

Refer to control board illustration,
is there 24VAC between P5(5) and P5(8) (blue and
brown wires) during the flame establishing period?
(
Note: Control Display must show “Heating” for
o
perating status)
Y
Replace
Control Board
N
Replace Rectifier harness
and/or
gas valve.
(see “Gas Valve
Replacement Procedure”)
N
Y
Does burner stay lit?
Can you hear or feel
g
as valve energize?
Does burner light
smoothly, without
evidence of coughing
or huffing?
Y
N
Check for obstruction
at inlet of gas valve.
Is inlet free of
obstruction?
Check flame sensor,
Is there 1 to 5 micro amps
(min.) during 1.5 second
flame proving period?
(Value may be displayed on
the control display by
accessing “Service Mode”)
N
Y
Continued from
p
revious page
N
Call for technical
support
Clear obstruction
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.
Y
Does burner operate
normaly until thermostat is
satisfied?
N
System OK
Y
SERVICE PROCEDURE EF-II
Combustion System Testing and Replacement
Turn VENTURI set screw clockwise until its
bottomed out. Turn screw counter-clockwise 6-½
turns from bottom. (Note: Venturi adjustment screw
is not on the EF100T399 models)
Replace flame sensor
(see “Flame Sensor
Replacement
Procedure”)
Inspect burner tube, (see
“Burner Tube Inspection”)
N
Y
N
WARNING
120 volt potential exposure. Isolate the
appliance and reconfirm power is
disconnected using a multi-meter.
Y
Venturi
adjustment
I
nlet gas
pressure tap
46
For models with Direct Spark System
12
3
8
6
5
4
3
1
1
2
1
4
1
3
3
2
1
1
5
3
P2P4P5 P7P3
CONTROL BOARD
P10P9J1
Flame
Sense Rod
CHECK FLAME SENSE
ROD MICROAMPS
Multimeter set to
microamp (ȝA) setting
Flame Sense
Terminal
46