Stiebel Eltron Water Heater Not Turning On [5 Reasons To Fix]

Uh-oh! Is your Stiebel Eltron water heater playing hard to get and leaving you shivering in the cold? Well, fear not! I’m here to rescue you from the cold by showing the reasons and solution to the issue – the Stiebel Eltron water heater not turning on.

So why isn’t the Stiebel Eltron water heater turning on? There can be 5 reasons behind this. They are – 

  • No power at the unit
  • Faulty wiring
  • Closed safety thermal cut-out
  • Tripped safety thermal cut-off
  • Old/bad thermostat

So, are you also looking for solutions to Stiebel Eltron water heater issues? Well for the power issue, turn on the circuit breaker or check the heating element. Again for tripped thermal cut-off, reset it.

The process of each solution is different. You’ll have to stay with us to figure out everything. So, let’s explore this guide on – the Stiebel Eltron wall heater not working.

Stiebel Eltron Water Heater Not Turning On: Quick Guide

Before I get into the detailed guide, here’s a table mentioning the problems and solutions at a glance. One thing to keep in mind: the solution is applicable for both tankless and mini-tank water heaters. I’ve indicated any specific considerations or special instructions where applicable for each type.

No Power at the Unit# Check and flip circuit breakers to the “On” position.
# Replace the heating element.
# Fix the electrical problem in the house.
Faulty WiringReorganize and fix the wiring according to the manual or wiring diagram.
Too much load on the heater# Don’t use too many appliances at once.
# Replace the heater with a more powerful one.
Closed Safety Thermal Cut-outOpen it by pressing the red reset button on the thermal cut-out.
Tripped Safety Thermal Cut-offReset the thermal cut-off buttons
Insufficient flow rateClean clogged faucet aerators, shower heads, and filter screens,
Bad ThermostatTest terminals for continuity and replace them if faulty.
stiebel eltron water heater not turning on

Stiebel Eltron Water Heater Not Turning On: Detailed Overview

From the above table, you’ve already got the basic idea. Now it’s time to explore the fixes in detail. If you’ve already figured out your issue, you can just skip all the problems and read certain ones. So, let’s dig in.

Problem 1: No Power at the Unit 

If the Stiebel Eltron Tankless Water Heater doesn’t have power, it won’t turn on. Usually, this happens when the circuit breakers connected to the water heater are turned off.

Again, if the heating element of the water heater is damaged then it can also cause the issue. Generally, it causes continual tripping, and therefore no power problem occurs.

Well, there can be other cases. If the fuse by any chance is blown then it can also occur. And finally, if there’s a problem with the electrical system of your house this problem can occur. 

How to Fix It:

Now let’s check how to fix the issue related to the circuit breaker. 

Step 1: First, inspect all the circuit breakers connected to the water heater. 

Step 2: Now, check the position of each water heater circuit breaker. If any of them are in the “Off” position, flip them to the “On” position.

Step 3: After turning on every circuit breaker related to the water heater, verify whether the unit is receiving power.

Step 4: If, even after turning on all the circuit breakers, the water heater still doesn’t have power, it means the fuse is blown or there’s a problem with the electrical wiring in your home.

Step 5: In the first case, you’ll have to replace the fuse. For the second case, contact a certified electrician and fix the electric problem of your house.

Now, if the problem is related to the heating element then the only solution is to replace the heating element. Stiebel Eltron comes with both tank and tankless models. If you’re dealing with a tank water heater changing the heating element will be difficult for you as you’ll have to disconnect the tanks.

So, whether you’re using a tank or a tankless water tank, I suggest calling for a professional or Stiebel Eltron customer support to replace the heating element. 

Problem 2: Faulty Wiring

This problem is very common. It’s very usual to mess up with the wires inside the electric panel. Again, if you manually try any fix regarding the heating element or the tripped reset button, there’s also a chance you mess up with the wires. In such conditions, there are high chance your heater won’t turn on due to faulty wiring.

How to Fix It:

Here the fix is just to reorganize the wirings. You can try to follow the manual or the wiring diagram to fix the wiring.

Problem 3: System Overload 

If you overload the water heater with more than its capacity the water heater may not turn on. Even though the heater turns on it will automatically shut down after supplying hot water for a few moments. Sometimes the heater can stop producing hot water

It’s not any problem, it’s because of loading the heater compared to its capability.

How to Fix It:

Here the fix is very simple. Don’t overload the heater. At a time, avoid using too many appliances. If you think it’s getting tough then I recommend replacing the water heater and this time, before purchasing, calculate the appropriate heater measurement for your household.

Problem 4: Closed Safety Thermal Cut-out

Some Stiebel Eltron water heaters come with closed safety thermal cut-out. For example, the Tempra 29 model has a “safety thermal cut-out” located on top of each heating element inside the unit. If the thermal cut-out is not open it might cause the heater won’t turn on issue.

How to Fix It:

To fix this issue, you’ll have to open it up and gently press the small red plastic push button on top of the cut-out. It’s important to be cautious and avoid touching any electrical wiring inside.

Problem 5: Tripped Safety Thermal Cut-off

In the previous part, I talked about closed safety thermal buttons. But it’s not always the reason. By any chance, if the unit excessively heats the water, it’ll result in a tripped safety thermal cut-off. And this is a reason why your Stiebel Eltron water heater won’t turn on.

How to Fix it:

To fix this problem you’ll have to reset the safety thermal cutout. Here’s a step-by-step guide on how to do it.

Step 1: First, turn off the power to the water heater at the circuit breaker to avoid any electrical hazards.

Step 2: Locate the front cover of the water heater and use a screwdriver to carefully unscrew and remove it.

Step 3: Inside the water heater, look for the reset buttons. These can usually be found on the top of the copper heating vessels. If you don’t find it just check the image under step 4.

Step 4: Now, take a pencil with an eraser and gently press the reset buttons. If a button clicks when you press it with the pencil, it means the reset has been successful.

press the reset button of stiebel eltron water heater with the pencil

Step 5: Once you have reset the buttons, securely close the front cover of the water heater.

Step 6: Return to the circuit breaker and restore power to the unit by turning on all the circuit breakers connected to the water heater.

Before I move on to the next segment if you are still confused about the resetting process, check out a comprehensive guide on how to reset the Stiebel Eltron water heater.

Problem 6: The Water Flow Rate Is Too Low

If the water flow is too low, the water heater may not turn on. This is especially true for tankless water heaters. They need a certain amount of water flowing through them to produce hot water. If the flow rate is too low, the water heater may shut off as a safety measure.

Let’s get a real example. To activate and provide hot water, the Stiebel Eltron Tempra 24 Plus model requires a minimum water flow of 0.5 gallons per minute (GPM). Without an adequate flow rate, it won’t turn or the heater won’t heat.

How to Fix It:

The insufficient flow rate I discussed generally occurs due to clogged filter screens, faucet aerators, or shower heads.

Your task here is very simple. Properly clean the components & the problem will be solved.

You can check the given video to learn how to clean a clogged faucet aerator without tools.

Problem 7: Bad Thermostat 

Your Stiebel Eltron water heater may not turn on if the thermostat is not working properly. The thermostat is responsible for controlling the water temperature inside the heater, and if it is faulty, it can prevent the water heater from functioning correctly. In a water heater with a single heating element, if the thermostat fails, there will be no hot water at all.

How to Fix it:

First of all, it is important to test the thermostat when the water heater stops working. Testing intends to figure out whether it’s receiving enough power or not. Let’s see how to do it. 

Step 1: Check and Reset the Tripped Reset Button 

  • Check if the reset button has been tripped. If it has then reset it.
  • Now, carefully disconnect the wires from the thermostat, and take note of their connections.

Step 2: Test the Left and Right Side Terminals

  • Take one lead of the multimeter and touch it to the left terminal next to the reset button.
  • Take the other lead of the multimeter and touch it to the other left terminal near the reset button.
  • If the thermostat is functioning correctly, the multimeter should show a reading close to zero, which indicates continuity. If it doesn’t, the thermostat is faulty and needs replacement.
  • Follow the same steps for the right-side terminals near the reset button.

Step 3: Test the Lower Portion of the Thermostat

  • Test the lower portion of the thermostat by touching one lead of the multimeter to the common terminal (next to the temperature setting) and the second lead to the left heating element terminal.
  • If the water temperature in the tank is below the thermostat’s set temperature, the multimeter should display a reading close to zero ohms, indicating continuity.
  • Move the lower lead from the left heating element terminal to the right heating element terminal. The multimeter should show NO continuity.
  • If the water temperature in the tank is above the thermostat’s set temperature, you should observe the opposite results.

Step 4: Test the Lower Thermostat

  • First, Disconnect the power wires connected to the lower thermostat.
  • Take the first lead of the multimeter, touch it to one terminal, and touch the second lead to the other terminal.
  • If the temperature of the water is below the thermostat’s set temperature, the multimeter should display a reading close to zero ohms and it indicates continuity.
  • If the temperature of the water is above the thermostat’s set temperature, the multimeter will display no continuity.
  • If you observe the opposite readings, it indicates a faulty thermostat.

Now after testing the thermostat if you find it faulty, just replace it.  


How to Turn on the Stiebel Eltron Water Heater?

To turn on a Stiebel Eltron heater, simply use the ON/OFF switch located on the right-hand side of the appliance. Flip the switch to turn the heater on or off as desired.

How to Reset a Stiebel Eltron Tempra® or DHC-E  Water Heater?

First, disconnect the power and open the case. For Tempra® and DHC-E models, the reset buttons are red or gray. In DHC, buttons are situated along the top right side of the heating vessel. Just, press it, and you’re done.

Do Tankless Water Heaters Turn on Automatically?

Tankless heaters remain inactive for the majority of the time and automatically activate whenever there is a demand for hot water.

How Can I Tell If My Electric Water Heater Is Not Functioning Properly?

Unusual noises coming from the water heater could indicate potential issues with the unit. These noises, such as popping, banging, or rumbling sounds, often result from sediment accumulation at the tank’s bottom.

Final Words

So, no more icy surprises as you now know why the Stiebel Eltron water heater not turning on and how to fix the issue. 

Before I leave now I’ve got 2 tips for you. First, properly maintain your water tank, and second choose the right size water tank according to your demand.

Well, if you face other issues with your heater aside from the not turning on issue, you can check our complete guide on Stiebel Eltron tankless water heater troubleshooting.

You’re welcome there! Good Luck!

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