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Lennox · Furnace

Red LED off No power to control or board fault

High severity Lennox EL195UHNE

What the control is telling you

Red LED is dark: the control has no power or has detected a board fault.

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

Likely causes

  • No 120 V supply (breaker, switch, door interlock open)
  • Tripped 3 A 24 V circuit breaker CB8
  • Failed transformer T1
  • Failed integrated control

Test and repair steps

  1. Check the blower door is on (door interlock S51 is in series with line voltage).
  2. Check breaker/disconnect and 120 VAC at the control LINE and NEUTRAL terminals.
  3. Check and reset circuit breaker CB8 (3 A at 32 V) in the control box; if it trips again look for a 24 V short.
  4. Check 24 VAC output of the 40 VA transformer.
  5. If power is present and the LED stays off, replace the control.

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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. Summarized in our own words; check the original manual for your model.

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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.