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Furnace Blinking 4 Times (4 Flashes)

Four flashes on a furnace LED usually means the high-limit switch opened from overheating — most often a dirty filter. On Goodman and Daikin, the same fault may show as code E3 on a 7-segment display.

Reviewed July 2026

What does furnace blinking 4 times (4 flashes) mean?

Four-flash patterns indicate the furnace overheated and the limit switch tripped. Restricted airflow from a clogged filter is the most common cause. On newer Goodman, Amana, and Daikin boards, the identical fault may read E3 on the display instead of four LED flashes.

What usually causes furnace blinking 4 times (4 flashes)?

High-limit switch openedmost common

Typical repair: $150–$600

Rollout switch trippedcommon

Typical repair: $150–$600

Restricted airflow from dirty filtercommon

Typical repair: $20–$75

Find your exact error code

Select your furnace brand to jump to the code page for this symptom.

Goodman4 FlashLimit circuit openedAmana4 FlashLimit circuit openedDaikin4 FlashLimit circuit openedTempstar4 FlashLimit or rollout circuit openHeil4 FlashLimit or rollout circuit openLuxaire4 BlinksLimit circuit openedYork4 BlinksLimit circuit openedComfortmaker4 FlashLimit or rollout circuit openKeeprite4 FlashLimit or rollout circuit openDay & Night4 FlashLimit or rollout circuit open

What should I check first when furnace blinking 4 times (4 flashes)?

  1. Replace the air filter immediately — this is the most common fix.
  2. Open all supply vents.
  3. Select your brand below to confirm what four flashes means on your unit.
  4. Wait 30 minutes after a limit trip before retrying.

What a repair costs

A limit switch replacement typically costs between $150 and $600 nationally.

Typical repair cost
$150 – $600limit switch replacement
Where the money goes
Part $20–$80Labor $70–$580Typical labor time: 1–2 hrs

This is general information, not professional advice. Gas, electrical, and combustion repairs can be dangerous — when in doubt, call a licensed technician.