HVACopediaLennox · Furnace
13 flashes Low line voltage
What the control is telling you
Line voltage is too low. Below 70 V the control will not answer a heat call until voltage is above 75 V; cooling continues.
Applies to: EL195UHNE furnaces with ignition control 103217-03 or 107163-01 (red LED)
Likely causes
- Low utility voltage
- Loose connections or undersized wiring
- Generator/inverter supply
Test and repair steps
- Measure line voltage at the control hot to neutral should be 97-132 VAC.
- Check breaker, disconnect and connections for voltage drop under load.
- Correct the supply; heating restarts once voltage is back above 75 V.
Settings for these units
Filter sizes (filter rack kits) · Lennox EL195UHNE
| Cabinet | Horizontal end rack | Side return rack |
|---|---|---|
| B width (040, 060) | 18 x 25 x 1 (kit 87L96) | 16 x 25 x 1 (kit 44J22) |
| C width (080, 100) | 20 x 25 x 1 (kit 87L97) | 16 x 25 x 1 (kit 44J22) |
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
- 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
- 11 flashes Pressure switch stuck closed before inducer starts
- 12 flashes Flame sensed with gas valve off
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Source: Lennox EL195UHNE Unit Information Corp 1801-L1 (rev 04/2024), Table 4 (103217-03) / Table 5 (107163-01) diagnostic codes, p.8-10; flowchart p.51-52. Summarized in our own words; check the original manual for your model.
Homeowner looking at this code? See what it means for you and when to call a technician.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.