Junkers Boiler Error E9

What does this error affecting your Junkers boiler mean?

Hello, how are you? Do you have a problem with your Junkers boiler that you haven't been able to solve? Well, you don't have to worry because that's why we're here. At Error Codes Ultimate, we care about our users' appliances, and we're going to help you solve any problem you may have with your boiler.

The E9 error code affecting Junkers boilers is a safety warning that our boiler gives us, something like: "Hey, I need a little attention here." This code is the alarm signal indicating that the temperature limiter has been activated. This limiter is a safety mechanism that prevents major damage to your boiler, but what causes the limiter to trigger? Let's see what could have activated it!

These are the causes that can trigger this error on the screen, take a look at them before starting the repairs:

• Lack of water in the system: If the boiler doesn't have enough water, it can't perform its heating function efficiently, so it may overheat and display the error on the screen.
• Presence of air bubbles: Bubbles can prevent proper water circulation and cause localized overheating in the circuit of your Junkers boiler.
• Defective circulation pump: A pump that is not functioning correctly cannot move the water, leading to a temperature increase and consequently an error code on the screen.
• Dirty or damaged temperature sensors: If the sensors are not in optimal working conditions, they will give you wrong readings and activate the temperature limiter of your boiler.
• Faulty PCB electronic board: A failure in the electronic board can cause incorrect readings and false positives that trigger the temperature limiter.

These causes are what can cause a temperature limiter to trigger. Basically, the boiler believes that there may be a fault that could damage the internal components of the device, and that's why, as a safety measure, it shuts down and displays the error on the screen.

What could be the solution to the E9 error code problem in the Junkers boiler?

To solve this problem with your Junkers boiler, you can follow these steps that we're going to outline below. Find the solution to this problem here and follow all the steps exactly:

1. Turn off and disconnect the boiler to rule out any temporary errors: Sometimes boilers have false positive errors due to electrical voltage problems or occasional electronic failures. This procedure won't take you more than 15 minutes, so let's try this first since it's not invasive for your boiler or anything like that. To do this, you just have to disconnect the boiler from the power outlet for at least 15 minutes. Once the recommended time has passed, you can reconnect the boiler and turn it on to check if the problem has disappeared. If, on the contrary, the problem persists, then please continue with the steps we're going to provide below.
2. Check the water supply and make sure the flow is adequate for your boiler to operate: Check the water pressure your boiler needs to operate, you can do this in the Junkers manufacturer's manual and according to the model of your boiler. You have to ensure an active and functional water supply to your boiler to avoid any problems that may arise due to overheating. Remember that the boiler also cools down with the same water that passes through the circuit, not just with the hot air it expels. Also, check that the shut-off valve, both the general one in your home and the one for the boiler itself, is completely open. Also, check the water flow and ensure it is adequate for optimal operation. If you have the shut-off valves completely open and the water comes out very little and/or weakly, contact the company that supplies you with water to verify that everything is fine.
3. Bleed the system to remove any accumulated air bubbles in your boiler's circuit: If you have air trapped in the boiler's circuit, it won't be able to work consistently, causing other problems to appear on the device's screen. The boiler has (depending on the model) an automatic process to bleed it, you will have to consult the manufacturer's manual to find out how you could do it. Otherwise, you will have to do it manually, opening the valve to bleed the boiler, waiting for all the air and water it may have accumulated to come out, and then resealing the valve. Air bubbles only interfere with the proper operation of your boiler, so you have to make sure you have completely eliminated them from your boiler's circuit.
4. Inspect the water circulation pump of your Junkers boiler: Check that the pump is working correctly and that it is not dirty or obstructed. Clean the pump and perform maintenance if necessary. Check the wiring going to and from the water pump and make sure it is in good condition, as well as ensuring that the connections are free of any sulfate. If you have electronics knowledge and have a multimeter, you can try checking if the pump is in good electronic condition, meaning it has continuity and receives power and commands from the PCB electronic board of your boiler.
5. Check the PCB electronic board of your boiler with a multimeter and using your advanced electronics knowledge: The electronic board is the brain of your boiler, the one that orders and sends commands to make it work and manage all sensors, heat, gas, water, in other words, absolutely everything is controlled by this board. It is possible that the board is damaged due to a short circuit and that you have to thoroughly check it with a multimeter. If you suspect that the board has a fault that you cannot repair, then it would be best to replace it with a new one that is compatible with your Junkers boiler model.
6. If the problem persists, please review everything mentioned above and follow the steps exactly: Please check that you have done all the steps properly, and that you have followed everything exactly as instructed. It is important to carefully review each point mentioned in this guide to rule out any possible cause that may cause this fault in your boiler. If you do not feel capable of doing all these checks, then it would be best to leave the problem in the hands of a professional.
7. Call Junkers technical support and request a home visit for a more thorough inspection of your boiler: If you have already tried all the solutions we indicated in this guide and the error with your boiler persists, then please contact Junkers so that technical service can help you solve this problem. A qualified technician will be able to diagnose the problem with your boiler accurately and carry out the necessary repairs, in addition to having the appropriate spare parts and tools for this task.

To summarize, we know that the E9 error code is an alert that something is not right with your Junkers boiler. The causes can be various, from lack of water to an electronic failure. To solve this problem, you can start with the basics: turn off, check, and adjust. Follow the steps in this guide, and you will surely find the solution to this problem.