Lennox · Furnace

E334 Y1 relay stuck on control

High severity EL296UHVLennox SL280UHV

What the control is telling you

Y1 relay on the integrated control is stuck.

Applies to: EL296UHV(X) series furnaces (integrated control 103130-XX and 107045-XX)

Likely causes

  • Failed relay on integrated control

Test and repair steps

  1. Confirm Y1 output stays energized without demand.
  2. Replace the integrated control.

Settings for these units

Recommended filter size by cabinet width · EL296UHV

Cabinet widthSide returnBottom return
17-1/2 in.16 x 25 x 1 in. (1)16 x 25 x 1 in. (1)
21 in.16 x 25 x 1 in. (1)20 x 25 x 1 in. (1)
24-1/2 in.16 x 25 x 1 in. (2)24 x 25 x 1 in. (1)

Number in brackets is the quantity of filters.

Filters are field supplied and installed outside the furnace; inspect monthly.

Recommended filter size by cabinet width · Lennox SL280UHV

Cabinet widthSide returnBottom return
14-1/2 in.16 x 25 x 1 in. (1)14 x 25 x 1 in. (1)
17-1/2 in.16 x 25 x 1 in. (1)16 x 25 x 1 in. (1)
21 in.16 x 25 x 1 in. (1)20 x 25 x 1 in. (1)
24-1/2 in.16 x 25 x 1 in. (2)24 x 25 x 1 in. (1)

Number in brackets is filter quantity; filters are field supplied.

Never run the unit without a filter installed.

Models that show this code

18 models in EL296UHV, Lennox SL280UHV

EL296UH045XV36BEL296UH070XV36BEL296UH090XV36CEL296UH090XV48CEL296UH090XV60CEL296UH110XV48CEL296UH110XV60CEL296UH135XV60DSL280UH060NV36ASL280UH070V36ASL280UH080NV48BSL280UH080NV60CSL280UH090V36BSL280UH090V48BSL280UH090V60CSL280UH100NV60CSL280UH110V60CSL280UH135V60D

Other codes on the same units

  • E310 Discharge air sensor failure
  • E311 Heat rate reduced for airflow
  • E312 Restricted airflow in cooling/fan
  • E313 Indoor/outdoor capacity mismatch
  • E331 Global network connection problem
  • E345 Relay O failure
  • E347 No 24 V on Y1 output
  • E348 No 24 V on Y2 output

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Source: Lennox EL296UHV(X) Unit Information / Service Literature, Table 5 Ignition Control 103130-XX Diagnostic Codes, p.37; Ignition Control 107045-XX Diagnostic Codes table, p.44. 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.