The flammable sensor can get triggered due to various reasons. Some of the most common causes include detecting flammable vapors, paint fumes, and loose wiring. It can stop the operation of the heater and you’ll have to reset it to solve the issue. So, how to reset Rheem water heater flammable vapor sensor?
From my own experience, I can tell you that the right process depends on the gas valve you’re using. You’ll have to follow different steps for White Rodgers valves and Honeywell gas valves. I’ve covered the FVS reset procedure for all the common gas valve types in this guide.
Apart from that, you’ll also learn about the most common reasons why the FVS keeps on tripping. You can be on the lookout for those issues and solve them when needed. So, let’s dive in!
Table of Contents
Why Does Rheem Water Heater Flammable Vapor Sensor Trip?
The flammable vapor sensor in water heaters is an important safety device. It’s a silicone-based sensor that detects fumes around the heater. If the sensor gets tripped, it’ll immediately cut off the gas supply. So, the heater will no longer be operational and you’ll run out of hot water soon.
The number one reason that the vapor sensor gets tripped is if there are fumes around the heater. Most people are aware of this sensor and that’s why they don’t store anything combustible near the heater. That’s good.
But what most people don’t realize is that fumes can travel. That’s why the sensor commonly gets tripped when some painting job is being done. Using oil paints or even normal paints can leave chemicals in the air. When they come close to the heater, the sensor gets tripped.
Even a good amount of dust can trigger this sensor. If you’re remodeling your house, the dust can block the vapor sensor. And it’ll get tripped in those situations and stop supplying gas to the gas control valve.
Apart from that, the FVS (Flammable Vapor Sensor) itself can be faulty. A defective gas control valve will also make the FVS trip.
How To Reset Rheem Water Heater Flammable Vapor Sensor [Explained]
The flammable vapor sensor is located right at the bottom of the unit. You should have no problem locating it. Here’s what it looks like:
Note: Not all Rheem gas water heaters have this sensor. It’s only added to specific models. So, if you can’t find this sensor, your unit doesn’t have one.
Now, keep in mind that there are different types of gas valves in water heaters. The Rheem flammable vapor sensor reset process varies slightly depending on the valve.
Follow the procedure for the gas valve you have. If you’re not sure which gas valve you have, just look at it. You’ll most likely have the name. Here’s you can reset the FVS in each of the different gas valves:
01. White Rodgers Gas Valve
This valve is the most common in the power vent models. Shut off the blower switch of the heater and disconnect the power cord of the heater. Wait for ten seconds and plug the power back in.
Then, wait for at least five seconds for the heater to get activated. After that, press both arrow buttons together and hold them down until the green LED light starts to blink. It usually takes 5 seconds to get there.
It’ll usually be the vacation that’ll blink. Then, you have to press the arrow buttons following a particular sequence. Here it is:
Left, Right, Left, Left, Right, Left, Right, Right.
Your FVS and the code in your heater should reset when you press the arrow buttons as shown above. It’s important that you do it in the right order to reset the heater. All the LED lights will illuminate if the code has been reset. If you see that, you did the job correctly.
02. Intelli Vent Gas Valve
The process of resetting the Intelli vent gas valve is similar to the last one. You have to unplug the power to the heater, wait for 10 seconds, and plug it back in. Then, you’ll press both arrow buttons together until the LED light starts to blink. Then, you have to let go of them.
From here on, the process will be different. Instead of pressing the arrow buttons in a sequence, you’ll press both of them together again. Hold them down for at least 5 seconds. That’ll reset the FVS.
Honeywell Gas Valve
The Honeywell gas valve is one of the most common gas valves in Rheem water heaters. The status light in the gas valve will usually flash 7 times when there’s an issue with the flammable vapor sensor. In that case, you have to reset it.
The process of resetting the FVS in this gas valve is a lot different from the other two. You can follow these steps to reset the FVS in a Rheem heater with a Honeywell gas valve:
- Turn off the water heater for at least 10 seconds and turn it back on. You can do it by removing the power plug and connecting it back. Or you can also move the gas knob to the “Off” position.
- Then, you have to do the next thing within 30 seconds:
- Turn the gas control knob to the “Very Hot” position. Then, go back to the “Off” position. Go back and forth like shown six times and make sure you do it in half a minute. That’ll reset the FVS in Honeywell gas valves.
Robert Shaw Gas Valve
If you have a relatively old heater, you’ll probably have this gas valve. The reset process is not a whole different than the Honeywell one. First, you have to turn the power off. Then, wait for 10 seconds, and turn the power back on.
Wait for at least 5 seconds for the heater to complete a self-check after you turn it on. Then, you can go back and forth with the gas control knob. Just like last time, you have to do it a total of six times. Once you follow these steps, the code should be erased and your FVS should be reset.
Why Does Rheem Flammable Vapor Sensor Keep Tripping?
More often than not, resetting the FVS should solve the issue. It should stay untriggered. But sometimes, it can keep on tripping. Here are the most common instances in which it happens:
Presence Of Flammable Vapors
If flammable vapors are still present, it’s common for the FVS to keep on tripping. It shouldn’t really come off as a surprise as it’s the main function of this sensor.
If you’ve been painting, then it’s possible that the paint fumes haven’t completely cleared out. That’s why the FVS gets tripped again and again. You have to get rid of the underlying issue as well if you don’t want the FVS to get triggered after you reset it.
Keep in mind that the FVS is a highly sensitive sensor. Even the smallest of things can trigger it. And that’s for good reason. Its job is to prevent fire-related accidents. It can save your life at crucial points.
Even the chemicals from cleaning agents can trigger the FVS. That’s why it’s advised to not store the heater in a laundry room. Moreover, if you smell any gas, there’s a serious possibility of danger. Evacuate your house immediately in that situation and call for help.
One thing you can do to keep the FVS from getting tripped easily is to place the heater about 20 inches from the ground. The flammable vapors are usually dense and they tend to settle at the bottom.
The FVS may not be able to pick up their presence from that distance. But that also defeats the whole purpose of using FVS. I don’t recommend that you do it for your own safety.
But if you’re sure that there are no such vapors and you want a temporary solution, you can try it. Do it at your own risk. And make sure you get to the root of the problem as soon as you can and fix it.
Presence Of Hydrogen
If you have not been using your heater for a while, hydrogen gas can be produced. The bad news is that hydrogen is extremely flammable. So, it can keep on tripping the sensor and keep the heater from starting.
As a preventive measure, you should turn the hot water faucet for a few minutes if it has been inactive. The timeline I am talking about here is usually two weeks or more than that.
So, make sure to turn on the hot water faucet for a while before plugging the power cord of the heater back in. You’ll notice unusual sounds like air escaping from the pipe if hydrogen is present. In that case, you shouldn’t proceed to turn on the heater. Call a qualified technician or contact Rheem customer service and get help.
Build Up Of Dirt
The flammable vapor sensor needs to be free of dirt and debris for it to work properly. It must not be blocked and have a good supply of air. If there’s any dirt or debris blocking the FVS, it’ll keep getting tripped.
You can try cleaning the FVS and see if that solves the issue. Pull it out of the heater and clean it using a soft cloth. If the sensor doesn’t get tripped anymore, the dirt was causing the issue this whole time. Now, you’ve solved it and you’ll no longer face this problem.
High Temperature
Both the ambient temperature and the temperature inside the combustion chamber have an effect on the FVS. It can’t work properly if either of them gets on the higher side.
The main reason behind the rise of temperature in the combustion chamber is when something is clogged. Make sure all the air inlet openings are okay. If any of them are clogged, vacuum the dirt out of them. That should take care of the problem and keep the FVS from resetting.
Loose Connection
The FVS needs to be connected properly to the wiring attached to it. If it’s loose due to any reason, it won’t work properly. It can constantly get tripped in that situation. So, make sure it has a tight connection with the wiring.
The wiring can also be faulty. You’ll have to replace the wiring in such cases. You’ll have to disconnect it from the gas valve and connect the new wiring back on. If you can’t do it on your own, consult a qualified technician to do it.
Faulty FVS
The flammable vapor sensor can also go bad after serving its lifespan. The FVS can also go bad and get locked out if it has severe exposure to flammable vapors. It’ll be beyond any repair at that time.
So, your only option is to replace it at that point. But before you do that, you should test it to make sure that it’s actually bad. I have dedicated sections on how to do both of these things in my Rheem 8 1 flashes error code guide. Visit that guide to learn more about it.
Faulty Gas Control Valve
Finally, it’s possible that there’s nothing wrong with the FVS and it can still get tripped. Even if there are no flammable vapors, hydrocarbons, or paint fumes. That happens when the gas control valve is faulty.
A bad gas control valve can throw off the FVS and make it trip again and again. You have to test the gas control valve to be sure that it’s bad. If it turns out to be faulty, you have to replace it too. Follow my Rheem gas control valve guide to learn all about it.
FAQs:
How to prevent the flammable vapor sensor from being tripped?
The ideal scenario here is to eliminate the possibility of flammable vapors being present. So, don’t store any combustible or flammable materials close to the area of the water heater.
What are some examples of flammable vapors?
Some obvious examples are gasoline, acetone, and alcohol products. But even things like adhesives, solvents, paint thinners, etc can produce vapors that can trigger the sensor.
Can the flammable sensor be tripped even if the vapors are far away?
Yes, natural air movement can carry the vapors through some distance. The main burner can ignite those vapors. That’ll immediately create a shutdown condition and the heater won’t work anymore.
Is it okay if the adjacent rooms to the water heater have flammable vapors?
No, the adjacent rooms and ceilings shouldn’t have any traces of flammable vapors. If they do, they can easily travel to the water heater and cause the shutdown condition.
How to make sure that the flammable vapor sensor lasts longer?
You can do it by avoiding damage to it. Make sure the sensor isn’t blocked by anything. Secondly, it should never be submerged underwater. So, use the drain pan to prevent that from happening.
Conclusion
How to reset Rheem water heater flammable vapor sensor? Now, you know the exact steps of doing it after completing this guide. Hopefully, resetting the FVS will get you out of the lockout condition and you’ll be able to use the heater again.
However, if it’s beyond repair, you’ll have to replace the sensor. Make sure you reset the gas control thermostat after you install the new FVS. Check out my Rheem dip tube replacement guide if you’re interested in changing it.