Midco International Inc.
11
8470 23
A. With motor running check burner line voltage terminals for 120 V as follows:
1. Between strip terminals
L1
and
L2
- 120 V: voltage OK.
2. Between strip terminals
L1
and
GND.TERM
- 120 V: ground OK.
3. Between strip terminals
L2
and
GND.TERM
. - no voltage: no backfeed neutral OK.
B. Follow test procedure as specifi ed in Step II G.
1. Connect DC microamp meter in series with sense wire and Electronic Control SENSE
terminal. With fl ame on, fl ame signal should be steady and at least 2 microamps. Check
sense wire for continuity Adjust ignitor gas pressure to obtain acceptable signal and note
gas pressure and signal strength for future reference.
A. Low gas pressure
B. Air shutter open too far
C. Input adjuster not set properly
A. High gas pressure
B. Air shutter closed too far
C. Insuffi cient free air in combustion chamber
D. Dirty blower wheel
E. Input adjuster not set properly
A. Defective automatic valve
B. High gas pressure
*Normal low voltage:
Motor running - 24 V minimum
Automatic valve energized - 21 V minimum
__________________________________________
IV Short Flame
V Long Hazy
Flame
VI Gas Fails to
Shut
O
ff
Trouble Chart
III Flame on Only
During 6-Second
Trial for Ignition
