CodeRegistry
Brands
  1. Home
  2. Lennox
  3. Communicating Systems
  4. 344
About·Privacy·Terms

CodeRegistry — Your global library for technical solutions.

For your safety: always follow the equipment manufacturer’s official manuals. CodeRegistry is an independent help site and is not affiliated with the brands listed here.

344

Alert Code 344 — Furnace Relay Y1 Stuck

Lennox · Communicating Systems

What does 344 mean?

This critical alert indicates a problem with the Y1 relay on the Integrated Furnace Control (IFC), suggesting a possible relay failure.

Common Causes

  • Y1 relay failure on IFC

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    The alert automatically clears five minutes after the Y1 input is sensed as OFF.

  2. 2

    If the issue continues after the auto-clear period, the IFC may need to be replaced. Contact a qualified technician.

Browse all codes in this manual (41)
Verified technical data. Last updated: April 2026

Related Faults

14Inverter Flash Code 14 (Red 1 flash, Green 4 flashes) — OD Inverter Compressor Slowdown21Inverter Flash Code 21 (Red 2 flashes, Green 1 flash) — OD Inverter DC Peak Fault262 red flashes, 6 green flashes — Compressor startup fail
Source: Lennox Communicating Systems
Open Manual (Page 46)Search more codes in this manual