HIGH URGENCY

Rheem Code 93 - Control Board Failure

Code 93

Internal control board failure.

Brand: Rheem (Also covers Ruud) | Equipment: Gas Furnace

What This Code Means

Code 93 on Rheem (Ruud) means the control board has detected an internal failure. Could be memory error, processor fault, or other internal issue. Board replacement typically required.

Likely Causes (Ranked)

Most common

Internal board failure

What: Internal component failure on control board.

How to check: Tech tests with multimeter; visible damage on board.

Fix: Replace control board.

Shop parts

Common

Power surge damage

What: Lightning or utility surge damaged board components.

How to check: Visible burn marks or damage.

Fix: Replace board; install surge protection.

Shop parts

Less common

Loose connection

What: Vibration loosened a connector causing intermittent fault.

How to check: Inspect all connections.

Fix: Reseat connectors.

Diagnostic Steps

Cut power 60s to attempt reset
If code returns, inspect board visually
Tech diagnostic
Replace board if confirmed failed

Frequently Asked Questions

Cost to replace Rheem control board?

$200-450 part plus labor. Often cheaper than expected if under warranty.

Same on Ruud?

Yes - identical board.

Can a power surge cause this?

Yes - consider installing surge protection to protect the new board.

Related Rheem Codes

Related Symptoms

Need More Help?

Try our interactive symptom diagnostic tool or browse Rheem parts.

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