Rheem Gladiator Water Heater Service Needed Light

Rheem Gladiator Water Heater Service Needed Light: What Does It Mean

You get the Rheem Gladiator Water Heater that helps you heat the water. The best part of this water heater is- you can operate it with ease because of its digital control. If you take a look at the digital display, you can find a feature there named Service Needed Light. 

Do you know the work of the Service Needed Light? Well, this Service Needed Light will blink red or stay solid red whenever it detects a problem with your water heater. 

Below, I will discuss every in and out of the Service Needed Light feature of the Rheem Gladiator Water Heater. So, stay in tune with us till the end. 

Table of Contents

Rheem Gladiator Water Heater Service Needed Light: What Is It?

Service Needed LED, as the name suggests, is the blinking indicator that will blink red or remain solid red if something is going wrong with your Rheem Gladiator Water Heater. The Service Needed Light will flicker because it needs service or your attention to solve a specific problem your water heater is going through. 

Whether the Rheem Gladiator will blink red or solid red basically depends on the type of error that has occurred. Two types of errors happen on Rheem Gladiator Water Heater. They are: 

  • Alert (Solid Red)
  • Alarm (flashing red)

I will explain everything that causes the Service Needed LED to blink red or remain solid red. Plus, I will walk you through the troubleshooting steps to fix those problems. So, keep reading. 

Rheem Gladiator Water Heater Error Codes: The Explanation

As I mentioned above, two types of error codes are displayed on the Rheem Gladiator Water Heater- Alert and Alarm. And the Alarm codes are categorized into five. In this chapter, I will break down both types of error messages. 

01. Solid Red (ALERT)

The ‘Service Needed’ light comes on and stays solid red on your Rheem Gladiator due to the following reasons: 

  • Disconnected leak sensor
  • Leak detected or the 24-hour Leak Detection Override gets activated
  • Wi-Fi or communication control error
  • Configuration data store failure
  • Configuration write limit exceeded

Forget to mention that, your Rheem Gladiator Water Heater will still be operational once the blinking indicator (Service Needed LED) will remain solid red. 

How To Fix: 

Start with checking the leak sensor for detachment. Just open the lower cavity and see if the leak sensor comes off or not. If yes, just connect it. On the other hand, if there is an issue with the wi-fi, you need to reset the connection. 

Luckily, I covered a complete guide on Rheem Gladiator Solid Red Light where I broke down what you should do in case of leak detection or how you can deal with Wi-Fi problems. So, you can check that article. 

02. Service Needed LED Flashing Red 1 Times (Alarm)

If the Service Needed LED blinks 1 red followed by a pause, understand the lower thermistor gets disconnected from the unit. Either way, failure of the lower thermistor can also be the culprit that causes the blinking indicator to flicker red 1 time. 

How To Fix: 

I highly recommend you call a professional plumber to solve the lower thermistor issue as it requires skills. Alternatively, you can call Rheem Customer Service to get the solution to this problem. 

03. Service Needed LED Flashing Red 2 Times (Alarm)

One of the following reasons cause the Service Needed light to flicker two consecutive red lights followed by a pause: 

  • The rope sensor comes in contact with water. 
  • The shut-off valve is in the close position and the water heater gets disabled. 
  • Fail to close the shut-off valve
  • Fail to re-open the shut-off valve

How To Fix: 

If the rope sensor senses water, it means there is water in the pan. Inspect the water pan for water and collect the water if needed. Don’t forget to dry the pan. Regarding this, you can use a dryer or a shop-vac to blow away the water. 

On the other hand, if the shut-off valve issue is the culprit behind the flicker of service-needed light, I suggest you call a certified plumber to solve this problem. 

04. Service Needed LED Flashing Red 3 Times (Alarm)

3 consecutive blinking red lights on Rheem Gladiator Water Heater mean there is no water in the tank. What you need to do is- just refill your water heater tank to stop the red blinks and operate the unit normally. 

How To Fix: 

Refilling the water heater will stop the red blink. Just turn the water heater on and open the water supply valve to your heater. Once the tank is full, close the water supply valve. Keep in mind; the drain valve and the pressure relief valve should be in a close position while you fill the tank with water. 

05. Service Needed LED Flashing Red 4 Times (Alarm)

If the water heater blinks red 4 times, understand your water heater is going through one of the following issues: 

  • Wiring to the upper, lower, or ECO gets disconnected.
  • Cross wiring to the upper and the lower element
  • ECO gets tripped 
  • The upper or lower element is at fault

How To Fix: 

Begin with checking the wiring to upper, lower, or ECO for disconnection. If needed, reconnect the wiring. However, you can call a professional electrician to do this task for you if you are not electrically inclined. 

For a tripped ECO, you need to reset it. 

And lastly, take a look at the upper and lower elements. If they are at fault, you should replace them. This article on Rheem Water Heater Element Replacement will come in handy to change the heating elements.

Alternatively, you can hire a professional to replace the elements if you are not mechanically inclined. 

06. Service Needed LED Flashing Red 5 Times (Alarm)

The Service Needed Light will blink red 5 times followed by a pause due to the following reasons: 

  • The relay of the upper or lower element gets stuck on
  • Temperature conversion error
  • Conversions drift error
  • On-board temperature protection error
  • The upper thermistor gets disconnected or defective

How To Fix: 

Each of the water heater problems that cause the Service Needed Light to flicker red 5 times demands professional skills to deal with. So, it will be best to call your plumber to handle this issue. 


Service Needed Light on Rheem Gladiator Water Heater will blink red or remain solid red when one of the parts of the heater starts malfunctioning. 

And I broke down every reason that causes the Service Needed Light to flicker red. As a result, you can easily detect the problem of the unit and take the initial steps to solve the issue. 

If you have any questions about this topic, don’t hesitate to leave a comment below.

PS: Please, Buy Me A Coffee to support my effort. It will encourage & help us to create helpful guides that will make your life simple.

Read Also: 

Rheem Gladiator Water Heater Troubleshooting 

Rheem Tankless Water Heater Error Codes

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  1. I was painting the bricks on the bottom of my Rheem gladiator electric hot water heater and the Red light came on and the Alarm beeped. (I must have got a drop of paint on the bead sensor) I silenced the alarm but the Red light is still on. The water heater is not leaking. How do I get the Red light to go out?

    1. Hello, Brian..

      The red light will come on for several reasons. If the leak sensor gets disconnected, the red light will start flushing. As you were painting the bricks on the bottom of your heater, may be you disconnect the leak sensor accidently while painting. Regarding this, reconnecting the leak sensor will solve this issue. I suggest you read the following guide where I already described why the red light comes on and how you can solve it:


      Hope, it will help you resolve the issue.

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