2 flashes Improper earth ground

What the control is telling you

The control does not see a proper earth ground. Heat will not run; cooling continues. A poor ground also shortens ignitor life.

Applies to: EL195UHNE furnaces with ignition control 103217-03 or 107163-01 (red LED)

Likely causes

• Missing or loose equipment ground
• Poor ground at the panel

Test and repair steps

1. Warning: Disconnect power before working on ground connections.
2. Check the green ground wire at the furnace and back to the panel; tighten connections.
3. Check ground at the control AC volts between line neutral and the C terminal should be about 0.3 V (2 V max) at idle, 0.75 V (5 V max) with inducer/ignitor on, under 2 V (10 V max) with blower on; line hot to neutral should be 97-132 VAC.
4. Repair the ground before operating the furnace if readings exceed the maximums.

Settings for these units

Filter sizes (filter rack kits) · Lennox EL195UHNE

Filters are field supplied; check monthly.

100NE60C over 1800 cfm with single side return needs a 20 x 25 x 1 filter via return air base and transition.

Models that show this code

4 models in Lennox EL195UHNE

Other codes on the same units

• 1 flash Line voltage polarity reversed
• 3 flashes Burner failed to light or lost flame
• 4 flashes Low flame signal
• 5 flashes Watchguard - ignition retries/recycles exceeded
• 7 flashes Primary or secondary limit open
• 8 flashes Rollout switch open
• 9 flashes Pressure switch stays open or drops out on a heat call
• 10 flashes Watchguard - pressure switch opened 5 times in one heat demand