If the status light in your Rheem gas heater blinks nine times, it indicates one of the two issues. Either there’s a failed chamber sensor or the bimetal switch was activated. More often than not, it’s the first issue.
So, what causes Rheem water heater chamber sensor failure & 9 flashes? From my own experience, I can tell you that it fails when you have used your heater for a long period. Besides, it can also be loose or dirty and trigger the error code.
You’ll learn all about you can test and replace the chamber sensor with all the details in this guide. So, let’s dive in!
Table of Contents
What Is A Chamber Sensor?
You may come across different terms like temperature sensors and thermocouples. As a homeowner, it’s normal to get confused by these terms as they have pretty much the same meaning. And when you throw the term – chamber sensor into the mix, it only gets more difficult. So, let’s break it down.
The chamber sensor is essentially a flame sensor. It’s only called a chamber sensor because it’s located inside the burner chamber. Apart from that, it works just like a normal flame sensor. Here’s a picture of a chamber sensor kit so that you can get a better idea of it:
It detects heat from the burner and sends a small current. That small current acts as a signal to send more gas to the heater. So, the main job of the chamber sensor is to regulate the flow of gas to the burner.
When it goes bad, the burner won’t get enough gas. So, you’d get colder water compared to your desired temperature when you have a bad chamber sensor. When the matter becomes too bad, the status light in your Honeywell gas control valve can flash 9 times and signal the error code.
Rheem Water Heater Chamber Sensor Failure & 9 Flashes [How To Fix]
When the status light in your heater indicates that the chamber sensor has failed, the issue is either with the sensor or the gas control thermostat. The most likely scenario is that either the sensor is dirty or has completely failed.
If the sensor is dirty, you can try cleaning it first. But if it has completely failed, you’ll have to replace it. Even if cleaning the chamber sensor does the trick in the short run, you should replace it as it’s a long-term solution.
If you only clean it, the sensor can get dirty again and cause issues. Besides, chamber sensors aren’t too expensive and you’ll find them within $30-$40. As they won’t leave a dent in your wallet, it makes sense to replace them altogether.
What you don’t want is the gas control valve to be bad. If it’s faulty, you’ll have to replace it as well. It is quite expensive. So, it’s important that you test the chamber sensor and make sure it’s actually bad. Otherwise, the gas control valve can also be at fault and you’ll waste time replacing the sensor.
How To Test Rheem Chamber Sensors?
If you have a multimeter, you can easily test the chamber sensor in your heater. You’ll also need the manufacturer’s chart so that you can check if the resistance reading is in alignment with the proper temperature. Here’s a general guide on what the reading should be at different temperatures:
But keep in mind that the specific reading for your heater can be different. So, you need to collect the one from your manufacturer for your particular model. Once you’ve managed these two things, you can follow these steps to test the chamber sensor:
- Turn off the gas control knob of the heater to the “Off” position. Shut off the gas supply and the power supply to the heater.
- Disconnect the wire of the chamber sensor at your gas control thermostat.
- Take a multimer, set it to the lowest Ohm settings, and use the pin probes required to test the chamber sensor.
- Connect the pin probes to the connector pins and collect the readings.
- If the reading is within the specified range, the chamber sensor is fine. Otherwise, it’s bad.
If the chamber sensor is fine and you still see the gas control valve flashing a red light 9 times, it’s most likely due to a bad gas control valve. You’d have to test it and replace it if it’s damaged. Check out my Rheem water heater gas valve guide to learn how you can do all of that in detail.
How To Clean a Rheem Chamber Sensor?
If the test reveals that you have a bad chamber sensor, that doesn’t always mean you’ll have to replace it. The first possibility is that it’s simply dirty or may have even gotten loose.
It’s common for chamber sensors to get dirty with time as soot builds up inside the burner. You can easily fix the chamber sensor by cleaning it. The unfortunate thing with Rheem heaters is that you’ll have to take out the entire burner assembly to access the chamber sensor.
So, that’s what you’ll have to do. Once you have located the chamber sensor, you can clean it using fine-grit sandpaper. If it is dirty and you have successfully removed the debris, it should work properly from there on.
Here’s a picture of the sensor to help you identify and isolate it from the other parts:
While you’re at it, make sure the chamber sensor is connected tightly. It shouldn’t wiggle if you give it some pressure with your hand. If it does, you need to tighten it.
If doing those things doesn’t work, that means it’s already too late to salvage the chamber sensor. Your only option is to replace it to get your heater to work properly once again.
How To Replace Rheem Chamber Sensor?
The good news is that replacing the chamber sensor is an easy job. The bad news is that it’ll take a while to do the job. That’s because you’d have to take off the entire burner assembly to access the chamber sensor.
That’s right – you can’t just unthread the sensor from outside. Don’t worry, I’ll cover all the steps you’ll have to take to complete the replacement. Here’s how you can replace the chamber sensor on your own:
Step 01 – Prepare The Main Burner For Removal
Turn off the gas and water supply to the heater. Wait for the heater to cool down before you start working on it. As you’d be removing the burner, doing so while it’s hot can cause injuries.
Remove the four T20 Torx screws securing the burner access door in place. Then, remove the different wires connected to the gas control thermostat. Use adjustable wrenches to disconnect the burner gas supply tube from the thermostat. Then, remove the top screw in the middle of the burner door.
Step 02 – Remove The Old Chamber Sensor
Gently pull out the burner assembly from the heater. Once, you get the burner out, you have to locate the sensor. You’ll need a ½ inch wrench for the inside. You’ll also require a 13-inch wrench for the outside part of the sensor.
You should be able to remove these sensors easily. You may also be able to get the job done using pliers. But it’s better to use wrenches to be on the safe side and get a good lock on the parts.
While you’re replacing the sensor, you can take your time to clean the burner as well. Though it’s not a part of the main job here, you should clean the burner as often as you can. That’ll make your heater last a long time. So, take a wired brush and get as much dirt out of the burner as you can.
Step 03 – Insert The New Chamber Sensor
Now, place the new sensor in place of the old one. You should have a clear idea of how to put it in as you took out the old one. Tighten the sensor by hand at first and then, use the wrenches to secure the sensor’s position.
With the sensor replaced, you can put the burner back in. Tighten the four screws and the screw in the middle. Connect all the wires and gas tube connections you removed at the gas control thermostat.
Once you do all these things, your status light should stop flashing. Hopefully, you’ll be able to light the pilot and use your heater from there on.
Sometimes, just replacing the sensor won’t get rid of the error code. You’d have to replace the gas control thermostat as well in those situations.
Check out my Rheem gas water heater thermostat replacement guide. You’ll find all the instructions you need to test and replace the gas control thermostat in that post.
FAQs:
Are thermocouples and flame sensors the same?
While their function is similar, they’re not the same. In gas heaters, a thermocouple usually senses the flame from the pilot light. Whereas the flame sensor senses the flame from the main burner.
Do Rheem gas water heaters have a reset button?
Not just Rheem but most gas water heaters won’t have any reset button. You’d have to turn off the gas supply to the heater, wait for a few minutes, and turn on the heater again to reset such heaters.
Is it dangerous when the chamber sensor fails?
The temperature of the water can be too high or too low when there’s a bad chamber sensor. So, there’s the chance of scalding with extremely high temperatures and that’s dangerous.
How long do Rheem chamber sensors last?
It depends a lot on how actively the heater is used along with its frequency. But you can expect it to last for 2-5 years on average.
Is the burner chamber sealed in a Rheem gas water heater?
Yes, the burner chambers in Rheem gas heaters are sealed using a gasket. There are also some tamper-resistant screws to seal the chamber fully.
Conclusion:
Now, you know everything there is to know about the Rheem water heater chamber sensor failure & 9 flashes issue. You can now diagnose the issue and take corrective steps. At times, cleaning the sensor will be enough. During other times, you’ll have to replace it.
Hopefully, this guide will help you in solving your problem correctly and quickly. You can check out my Rheem gas heater troubleshooting guide if you’re facing other issues with your heater.