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

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.

Perfect, our water heater started shut off when turning on the house heater since they are in the same room. The sensor was so easy to change, works perfect. Saved a lot of money doing it ourselves.

Worked perfectly on my Rheem. There is another on this site that shows the same part number but will not work on Rheem hot water heaters, Don't buy it. You will be disappointed. buy this one. It works perfect

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 😀

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.

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!

Let me start by saying "IT WORKED"!! This is important because at 11pm on a Thursday (before Memorial Day no less) my daughter discovered the hot water heater had quit working the hard way. She had to rinse off in ice cold tap water. I diagnosed the problem and had the part on order through Amazon by midnight for expedited delivery on Saturday. Friday, with no hot water was not great for the whole family. Saturday, the part arrived, I installed it and viola! Hot Water. My Richmond water heater, only about 3 years old, was indicating a FVS Lockout on the Honeywell Controller. FVS is the Flammable Vapor Sensor, something common to pilotless models to make sure there are no leaks before igniting. That is a good thing when it functions right. Its also a good thing when it fails that it prevents operation. Well, except for the cold showers, its a good thing. This set comes with the housing around the actual sensor. Why, because you can remove the old housing from the water heater itself, but the way the FVS installs in the housing you would destroy the housing removing the defective FVS. So the housing is there for a reason. The same thing for the tie wrap. You'll need to remove your wiring harness from the control unit, then carefully use pliers to pull the wire connectors from the defective FVS. I installed the harness first because I wanted to be careful to connect to the right terminals. I don't know that it matters, but I did not want to take a chance (two days without hot water if you recall). I carefully feed the harness through the housing and easily snapped the FVS in place. The chamfer on the edge of the FVS should allow easy insertion, but the blade (terminal) side goes into the housing FIRST. The part numbers were not an exact match, but cross checking indicated this to be a new replacement for my defective one. Hopefully the part number difference indicates a new and improved part. These things seem to have reliability issues. I guess over three years to savings in natural gas was worth it. Finally, I checked Amazon for this part in desperation. No one locally had it in stock. I could order the it might arrive the Tuesday or Wednesday after Memorial Day, leaving us without hot water for nearly a week. Thankfully Amazon exists and has priority shipping. No matter what a certain world "leader" thinks, Amazon exists due to this extreme level of customer service. If brick-and-mortar stores would actually take customer needs and service seriously, they would not have these problems. I prefer to buy local when I can. No hot water makes expedient service all the more important.

Great sensor with excellent performance.

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