Rheem SP20172 Flammable Vapor FV Sensor Kit White, 6.7X2.7X9.4 inches

This piece saved me a likely $150+ HVAC bill. One of my best purchases on here. I had my hardwood floors refinished and after I was able to return back my hot water heater wasn't working. I checked the controller unit and the flashing lights indicated I had a FVS Fault. I thought "well S***". (Appreantly the strong vapers from polyurethane sealant with hardwood refinishing can set this sensor off). I did a little research and decided to try and diy it. So glad I did. Installation was easy. Just a simple plug and play item. Then I reset my gas control unit and it worked instantly. Saved so much money and only took maybe 4 minutes. Works perfectly with my Rheem 50gal Professional Unit.

I've had two identical Rheem Platinum 50-gallon water heaters for almost 10 years. Every few years it seems, they shut down and throw a "Flammable Vapor Lockout" error, which is indicated by seven flashes of the blue light on the gas valve assembly. A reset of the unit will usually clear the code. However, when the error starts happening too frequently for my taste, it's time to replace the flammable vapor sensor. This time, I checked the old sensor with a voltage-ohm meter and got a reading of 97,000 ohms resistance. According to Google, the reading should be between 9,000 and 45,000 ohms. So, mine was definitely reading outside the acceptable range, which indicates a failure. I used to contact Rheem and wait several days for them to send me a new vapor sensor under warranty for me to install myself. But, the last two times I just bit the bullet and ordered the sensor on Amazon. For less than $30 (as of 2026) I can have my water heater back up and running within two days (thanks to Amazon's 2-day shipping). The actual brand name of these sensors is ProTech. It's a brand apparently owned by Rheem. So, you're getting the official genuine Rheem part when you order this one. There are at least two cheaper but viable replacement sensors available on Amazon as I write this. One of them is half the price of the Rheem sensor. But I don't recognize the brand names and much prefer the OEM Rheem brand when safety is involved. The new sensor has worked flawlessly since I installed it two weeks ago. Installation takes less than 10 minutes. I'll continue to buy these as long as necessary, rather than bother with the water heater warranty.

It’s hard to believe this little device can cause so much trouble. 😂 purchased my Rheem hot water heater at Home Depot 10 years ago. Had a pipe brake and cause the sensor to go out. Went to Home Depot to get the part and you guess it! Don’t carry it in stock in my area. And it would take a week to get it.. went to two places in town no one had it. Finally went to Amazon and purchased the sensor. Got it the next day! Hook it up in two mins. Or maybe less 😂 fired right up. Decided that’s never going to happen to me again. Ordered a back up. Maybe over kill! But maybe not. Will see 😀

I saw "Otto's Gang" post, and he thought what mattered was the gas valve as far as a compatible sensor, and his picture was the exact same valve on my Bradford White hot water heater, so I bought this sensor. While mine does not mount like the Rheem water heater, the sensor itself looked exactly the same, although there is a different part number stamped on it (I'm guessing because it's a different mount). My water heater has a black strap that clips to hold the sensor below the controller. This sensor was way cheaper than the one listed specifically for Bradford White, and it arrived really quickly where the other one was days for delivery. I'd definitely buy this sensor again; forget paying 5 times the amount for the same sensor with a different part number printed on it! Also, I ohmed it and kept getting different readings, I never got a 0 reading, while my old sensor did return a 0 reading. Thanks so much to Otto's Gang for the helpful review and the sensor seller for offering this value for money!

The replacement FV Sensor works fine on my 2012 Whirlpool gas water heater. This is the second time I purchased the same Protech part from Amazon. The first Protech replacement FV Sensor lasted four years. The original factory installed FV Sensor lasted ten years. Four stars for the comparatively short life cycle. The dimensions in the product title description refer to the plastic bag the sensor comes in. The sensors are easy to install, no tools required.

Bought competition cheaper version and could reset the heater. This one worked great

After replacing the sensor in 2025, I bought 2 spares in July 2025, one came in a small box, the other in a sealed plastic bag. I stored both by the water heater. Today the water heater quit with the 7 blink error code indicating lockout due to FV sensor trip. I was able to reset the controller but it tripped again after a few minutes of running. I installed the boxed sensor and it did not work. I installed the sensor from the SEALED bag and it worked fine. I suspect that exposure to the atmosphere over the last year may have degraded the one in the unsealed box just as the sensor in the heater itself had degraded over time. If you get one in an unsealed box, I'd recommend storing it in a sealed ziploc bag which may help keep it usable.

after removing your old sensor, your controller's status might change, e.g. "Flammable vapor sensor lockout" might become "FVS fault detected." if you have a multimeter, use it to verify that your old sensor does not satisfy the resistance requirement. (based on service bulletins i found, the acceptable range is 13-45kΩ). otherwise, you may assume that your controller is correctly reporting sensor status. cheap, aftermarket sensors are tempting but they are sketchy. after buying one that was DOA, i bought a *used* Rheem sensor from Amazon Resale. i think these sensors are often returned by people who neglect to reset their controllers. if you have a multimeter, use it to verify that the new sensor satisfies the resistance requirement. (mine measured 16.8kΩ.) otherwise, just install it. to facilitate returning this sensor: install the cap/plug and run the wires through it before connecting the sensor *without* completing sensor-cap/plug assembly. at this point, your controller will act as though this sensor is defective. the installation instructions (dated 01/09) describe how to reset older controllers, so you might have to find instructions for *your* controller. there are online videos ... with any luck, you'll hear gas burning soon :-)

This is a great product! It was very easy to replace and works perfectly. Best of all, it’s much more affordable than the same item listed on Rheem’s website. Just make sure to check with a professional to ensure proper installation. Not responsible for any misuse. Highly recommend if you’re looking for a reliable and cost-effective option.

Muy buen producto y dificil de conseguir pero en Amazon lo encontre inmediatamente y a un excelente precio comparado con otros proveedores

A plumber told me how to reset the gas valve when it locks up. Unplug the heater and use a slot screwdriver to turn down the thermostat all the way. Plug the heater back on and turn it all the way up, then back down. Repeat 3 times then turn it up 3/4s of the way. The heater fired right up. I kept the sensor and attached it to the gas line for the future. It seemed to make sense to keep the part which arrived the following day. Good of the plumber to tell me about the reset on the phone after a Sunday call and not charge us.

I bought one locally a few years ago for over 3x this price. Worked fine, easy to install even if you have no idea what you're doing, if you can plug an appliance into the wall you can install this. All you need is a flathead screwdriver to pry the old one off (you could use a butterknife also) Reminder than most tanks require a reset after installing so if you plug it in and its still giving you an error just initiate a tank reset. (Can check google for how to do so)

works perfect