What does Ruud code 22 mean?
Ruud furnace code 22 means the main limit circuit is open on the supported control family. Confirm the model number and diagnostic chart inside the furnace door before replacing parts.
What causes Ruud code 22?
- A dirty or overly restrictive air filter
- Closed or blocked supply and return vents
- A blower, limit switch, or airflow problem
Can I troubleshoot Ruud code 22?
- Turn the furnace off and replace a dirty filter with the size and type specified for the system.
- Open all supply registers and make sure return grilles are not blocked before trying one reset.
How much does Ruud code 22 cost to fix?
A limit switch replacement typically costs between $150 and $750 nationally.
When should I call a technician?
Call a technician if the limit code returns; repeated overheating can damage the furnace.
Sources and model scope
Fault codes vary by model and control board. Confirm the diagnostic chart inside your furnace panel or the official manual before acting.
Scope used here: Rheem/Ruud RGFG-family controls using the documented two-digit diagnostic table.
- Rheem Manufacturing Company: RGFG Series Gas Furnace Installation Instructions and Diagnostic Codes
92-24161-104-06 · Rheem/Ruud RGFG-family furnace controls; confirm the unit model and its door chart before applying a code meaning.
Compiled by Warmlo Editorial · Reviewed August 2026
This is general information, not professional advice. Gas, electrical, and combustion repairs can be dangerous — when in doubt, call a licensed technician.