Why Is My Rheem Water Heater Blinking Red Light?

Rheem Water Heater Status Light Blinking Red indicates a system problem. The number of red flashes on the status light will point to a specific issue you experienced with your water heater. 

For example: 

• The status light blinking red twice indicates the thermopile voltage is low.

• The status light blinking red four (4) times means a high-temperature shutdown.

• The status light blinking red five (5) times indicates a problem with the temperature sensor.

• The status light blinking red seven (7) times points to an issue with the gas control valve.

• The status light blinking red eight (8) times means a false pilot flame signal. 

• The status light blinking red nine (9) times will signal you that the chamber sensor is at fault.

• The status light blinking red ten (10) times means chamber temperature shutdown. 

Table of Contents

• What Does the Blinking Red (Status Light) Mean on Rheem Water Heater?
• What Causes The Status Light To Blink Red On Rheem Water Heater? 
  • 1. Low Thermopile Voltage (Status Light Blinking Red Twice)
  • 2. High-Temperature Shutdown (Status Light Blinking Red 4 Times)
  • 3. Temperature Sensor Failure (Status Light Blinking Red 5 Times)
  • 4. Gas Control Valve Failure (Status Light Blinking Red 7 Times)
  • 5. False Pilot Flame Signal (Status Light Blinking 8 Times)
  • 6. Chamber Sensor Failure (Status Light Blinking Red 9 Times)
  • 7. Chamber Temperature Shutdown (Status Light Blinking Red 10 Times)
• Is the Status Light Supposed To Blink On the Rheem Water Heater? 
• What’s the Proper Procedure to Light the Pilot on the Rheem Gas Water Heater? 

What Does the Blinking Red (Status Light) Mean on Rheem Water Heater?

The status light blinking red means a system problem on your Rheem Water Heater. The number of blinks on the status light will imply what problem you are experiencing with your Rheem Water Heater. 

Here is the table that includes the number of flashes on the status light and what they mean: 

Number of Flashes	Color	Status or Meaning
2	Red	Thermopile Voltage Low
4	Red	High-Temperature Shutdown
5	Red	Temperature Sensor Failure
7	Red	Gas Control Valve Failure
8	Red	Flame Sense Error
9	Red	Chamber Sensor Failure
10	Red	Chamber Temperature Shutdown

What Causes The Status Light To Blink Red On Rheem Water Heater?

The reasons that cause the status light to blink red are low thermopile voltage, high-temperature shutdown, and gas control valve failure. 

1. Low Thermopile Voltage (Status Light Blinking Red Twice)

The status light blinking red twice will indicate that the thermopile voltage is low. I recommend you test the thermopile electrically for low voltage. 

Go along with these simple steps to test the thermopile voltage: 

• Take a multimeter for direct current. Then, set the multimeter to millivolts.

• Wiggle the thermopile connector and pull it out from the gas control. 

• Attach the red positive lead to the red thermocouple wire and the black lead to the other (white) wire. 

• Now, light your pilot light according to the manual. 

• Depress and hold the thermostat knob down until it reaches the maximum voltage. It may need three minutes to reach the highest voltage. After that, the reading on your multimeter will start slowing down. 

• A healthy thermopile voltage reading should be 650 to 850 millivolts. A voltage reading anywhere below 400 millivolts will indicate that the thermopile is at fault. To resolve this issue, you should replace the thermopile. 

Once you get your replacement part in your hand, this tutorial will come handy: 

2. High-Temperature Shutdown (Status Light Blinking Red 4 Times)

Four (4) consecutive red flashes on the status light will indicate a high-temperature shutdown. This Rheem Water Heater has a Combination Gas Control (Thermostat) with a single-use gas shut-off device. 

When your water heater exceeds normal operating temperature, the single-use shut-off device will shut off the gas supply to the burner. As a result, the unit will turn off immediately and protect you against the scalding hot water. 

I highly suggest you contact the Rheem Support Team at 1-866-279-4566 if you experience the high-temperature shutdown issue with your water heater. 

3. Temperature Sensor Failure (Status Light Blinking Red 5 Times)

The status light will blink red five (5) times every three (3) seconds when the temperature sensor is at fault. Typically, this flashing red light indicates that the control valve is at fault. 

In other words, you need to replace the Combination Gas Control (thermostat) to resolve this issue. 

I recommend you call the Rheem Support Team to get the part number. Before you call them, ensure you have kept the model numbers and the serial numbers of the water heater at your fingertips. 

Once they confirm the part number, get the gas control from anywhere, like Home Depot or Amazon. Then, give 2 or 3 hours on DIY jobs like turning off the gas supply, draining the water tank, and disconnecting the gas control. 

It will be best to contact a certified plumber to replace the gas control as it requires a lot of tasks. 

4. Gas Control Valve Failure (Status Light Blinking Red 7 Times)

A faulty gas control valve causes the status light to blink red seven (7) times. 

Due to a defective gas control valve, the heater unit will not flow sufficient fuel to ignite the water heater. Consequently, you will get no hot water from the unit. 

To resolve this issue, you must replace the gas control valve. If you are mechanically inclined, you can find the following tutorial helpful: 

Alternatively, you can hire a certified professional to do this task for you. 

5. False Pilot Flame Signal (Status Light Blinking 8 Times)

Status light flashing  red eight (8) times indicates a false pilot flame signal on your Rheem Water Heater. You will experience this problem with your water heater when the pilot valve remains stuck in the open position. To fix this issue, replace the gas control valve. 

6. Chamber Sensor Failure (Status Light Blinking Red 9 Times)

When the chamber sensor is at fault, the status light will blink nine (9) times. It actually occurs due to a dirty chamber sensor or when its wiring comes loose. 

First, I recommend you check the tightness of the chamber sensor wiring. If the sensor wire connection is secure, I bet the chamber sensor is at fault. 

Regarding this, you must replace the chamber sensor. You should remove the entire burner assembly to make this replacement. Check out this tutorial to learn how to replace the chamber sensor on the Rheem Water Heater: 

7. Chamber Temperature Shutdown (Status Light Blinking Red 10 Times)

The status light will blink red ten (10) times due to chamber temperature shutdown. It actually occurs when the chamber sensor senses the temperature inside the chamber exceeds the safety level. 

It’s a complex problem that could happen due to a defective chamber sensor or a faulty gas control valve. So, I suggest you contact the Rheem Support Team for further assistance.

Is the Status Light Supposed To Blink On the Rheem Water Heater?

A blinking light doesn’t imply a problem all the time. Instead, you should notice what color flashes on the status light. 

In normal operating conditions, the status light will blink blue one (1) time every three seconds. If the status light doesn’t blink blue, relight the pilot. 

On the other hand, if the status light blinks red more than one flash, understand there is a system problem. I revealed the meaning of the red flashing code on the status light. 

What’s the Proper Procedure to Light the Pilot on the Rheem Gas Water Heater?

Follow the below step-by-step procedure to light the pilot on your Rheem Gas Water Heater: 

• Read the safety instructions labeled on your water heater tank.
• Turn the combination gas control (thermostat) knob counterclockwise to the Off position. 
• Wait five minutes to clear out any gas remaining in the plumbing system. 
• . Locate the piezo-electric spark generator button, which you can find below the gas control thermostat. 
• Press and hold down the gas control (thermostat) knob to the Pilot position. 
• Continue to press the igniter button until the pilot lights.
• Release the knob when the status light starts to blink. 
• Set the combination gas control/thermostat knob to the desired temperature setting. 

Related Articles:

• Rheem Water Heater Light Not Blinking
• Honeywell Water Heater Status Light Codes