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Heil 6 Flashes - Weak Flame Signal

6 flashes

Weak or non-existent flame sensor signal.

Brand: Heil (Also covers Tempstar, Comfortmaker, Keeprite, ICP, Day & Night, Arcoaire) | Equipment: Gas Furnace

What This Code Means

6 flashes on Heil/Tempstar/Comfortmaker means the flame sensor signal is too weak or absent. Usually a dirty flame sensor or failing igniter.

Likely Causes (Ranked)

Most common (~75%)

Dirty flame sensor

What: Coating prevents flame detection.

How to check: Pull and inspect for soot.

Fix: Clean with fine emery cloth.

Shop parts

Common

Failed igniter

What: Weak ignition produces unstable flame.

How to check: Watch glow brightness.

Fix: Replace igniter.

Shop parts

Less common

Low gas pressure

What: Insufficient gas produces weak flame.

How to check: Tech measures pressure.

Fix: Adjust or call gas utility.

Diagnostic Steps

Cut power
Clean flame sensor
Watch heat cycle
Replace igniter if no orange glow
Call tech for gas issues

Frequently Asked Questions

How to clean Heil flame sensor?

Cut power, pull sensor (one screw), wipe with fine emery cloth, reinstall. 5 minutes.

Same on Tempstar?

Yes - all ICP family.

DIY?

Yes - flame sensor cleaning is straightforward.

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Need More Help?

Try our interactive symptom diagnostic tool or browse Heil parts.

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