HIGH URGENCY

Heil 10 Flashes - Line Voltage Polarity Incorrect

10 flashes

Line voltage polarity incorrect - wiring or transformer fault.

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

What This Code Means

10 flashes on Heil/Tempstar/Comfortmaker/Keeprite furnaces means the line voltage polarity is reversed. Possible wiring, transformer, or control board failure.

Likely Causes (Ranked)

Most common

Hot/neutral reversed

What: Wires swapped at disconnect or home wiring.

How to check: Electrician test.

Fix: Correct wiring.

Less common

Faulty transformer

What: Internal transformer fault.

How to check: Tech tests output.

Fix: Replace transformer.

Shop parts

Less common

Bad control board

What: Board misreads polarity.

How to check: Tech diagnostic.

Fix: Replace board.

Shop parts

Diagnostic Steps

Cut power at breaker
Call licensed electrician
Verify wiring polarity
If wiring OK, call HVAC tech

Frequently Asked Questions

Same on Tempstar/Comfortmaker?

Yes - all ICP family brands share this code.

DIY?

Only if qualified for line voltage work.

Damage risk?

Can damage control board over time.

Related Heil Codes

Related Symptoms

Need More Help?

Try our interactive symptom diagnostic tool or browse Heil parts.

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