The SP20172 Flammable Vapor FV Sensor Kit is a dedicated replacement component designed specifically for FVIR (Flammable Vapor Ignition Resistant) water heaters from leading brands such as Rheem, Ruud, and Richmond. This kit, identified by the alternative part numbers AP13447-3 and 25VS, serves as a direct substitute for the original sensor assembly. Its primary role is to detect the presence of flammable vapors in the vicinity of the water heater and trigger the safety shut‑off mechanism, thereby reducing the risk of ignition. The kit is engineered to match OEM specifications, ensuring a precise fit and reliable integration with compatible water heater models without requiring modifications.

Constructed from durable, heat‑resistant materials, the sensor unit features a robust housing and a sensitive detection element that responds consistently to volatile organic compounds. The assembly includes a pre‑wired connector with a standard plug, allowing for straightforward installation by removing the old sensor and connecting the replacement. The metal and plastic components are selected for long‑term stability under typical water heater operating conditions, minimizing the likelihood of corrosion or thermal degradation. Each unit undergoes quality control testing to verify electrical continuity and sensor response, ensuring dependable performance throughout its service life. In operation, the sensor monitors the air around the water heater for elevated levels of flammable vapors, such as those from gasoline, paint thinners, or solvents. When vapor concentration exceeds a safe threshold, the sensor sends a signal that interrupts the burner gas supply, preventing combustion. This safety function is crucial for maintaining FVIR compliance and reducing hazards in garages, basements, or utility rooms. The response time is calibrated to industry standards, offering a balance between sensitivity and avoidance of nuisance trips. The compact form factor does not interfere with normal water heater clearance or airflow. At a price point of $17.93, this replacement sensor kit presents an affordable solution for restoring safety features in older FVIR water heaters. Compared to the cost of calling a technician or replacing the entire water heater, this kit offers significant savings. The straightforward design means most homeowners with basic hand tools can complete the installation themselves, further reducing maintenance expenses. The cost‑effectiveness does not compromise reliability; the sensor meets the necessary technical requirements for FVIR systems and is built to last through multiple heating cycles.

The SP20172 Flammable Vapor Sensor Kit provides a practical and economical means of ensuring ongoing protection against flammable vapor hazards. Its precise compatibility with Rheem, Ruud, and Richmond water heaters, along with its durable construction and straightforward replacement process, makes it a suitable choice for routine maintenance or emergency repair. The combination of verified functionality and accessible pricing positions this kit as a logical purchase for anyone seeking to uphold the safety standards of their FVIR water heater without overspending.