Rheem-Ruud SP20172 Sensor Kit

The Rheem-Ruud SP20172 Sensor Kit is the essential OEM replacement for managing flammable vapor ignition resistance (FVIR) in gas-fired water heaters. Designed as a direct supersession for AP13447-3, this flammable vapor sensor (FVS) monitors the environment for volatile substances, triggering a safe shutdown via the gas control valve if high concentrations are detected. A common indicator for a malfunctioning or tripped sensor is the seven-flash error code (7-3 lockout) on the status light. Unlike standard thermistors, this sensor requires a specific resistance level—typically 13k ohms or higher—to allow the burner to fire. Installation of the SP20172 water heater sensor restores safety protocols and prevents nuisance lockouts caused by moisture or environmental contaminants. This kit includes the necessary FV sensor assembly, terminal connectors, and a cap plug to ensure a secure, sealed interface with the existing harness on models like the PDV40 and PDV50 series.

• Critical Safety Compliance: Restores FVIR safety standards by detecting volatile gases to prevent accidental ignition.
• Direct Drop-in Replacement: Identical to AP13447-3 and AP19452, ensuring seamless integration with original Rheem-Ruud gas valves.
• Troubleshooting Solution: Specifically engineered to resolve soft lockout conditions and persistent 7-light pulse error codes.
• Precision Resistance: Factory-calibrated to meet the exact technical specifications required for modern digital gas controls.

How do I know if the SP20172 needs replacement?

If your water heater status light flashes seven times with a three-second pause, the gas valve has detected an FV sensor lockout. Use a multi-meter to check the resistance; if it reads below 13k ohms or shows an open circuit, the sensor is likely compromised and requires replacement.

Can I reset the sensor after it trips?

While some gas valves allow for a manual reset sequence (cycling the temperature dial), the manufacturer recommends total replacement of the SP20172 kit if the sensor was physically exposed to high concentrations of flammable vapors or high moisture to maintain system integrity.

Which models are compatible with this kit?

This HVACR specialized part is compatible with various Rheem, Ruud, and Richmond residential gas water heaters, particularly power vent (PDV) and atmospheric models manufactured after 2019 that utilize the updated FV sensor resistance profiles.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.