Lennox iComfort SL280UH070V36A Manual page 40

Test 1
Remove 5-pin plug from control
Check ohms reading across terminals 1and 5
Ohm value should be between 39 - 70.
Meter
(set to ohms)
Test 2
Seperate the 2-pin jack plug near the manifold
and check resistance of the ignitor. If the reading
is correct, then then there is a problem with the
wiring between the jack plug and control. If the
reading is not correct the issue is the ignitor.
Meter
(set to ohms)
Test 3
Insert meter probes into the terminals 1 and 5. (Use small
diameter probes in order to not damage plug). Check
voltage during 20 second warm up period. Voltage should
read 120 volts + 10%. If voltage is above these values,
check for correct supply voltage to furnace.
(set to AC volts)
SL280UH Ignitor Check Out
.
Meter
FIGURE 14
Integrated control detail
Page 40
Integrated control detail
Integrated control detail