Dishwasher not heating water? Causes and solutions
Do you open the dishwasher immediately after the programme is finished, and no cloud of steam comes out? Do the plates feel ice-cold and is the grease still there? A dishwasher that no longer heats is essentially useless. Grease and food residues simply do not dissolve in cold water, and without heat, your dishes cannot dry.
Fortunately, the culprit for cold water is often quickly identifiable. Below we go through the most common causes, from simple blockages to a faulty heating element.
What you can check yourself first (Free & Quick) 🛠️
Before you book a repair, there are two things you should rule out yourself:
1. Clogged filters at the bottom
This may sound illogical for a temperature problem, but it is crucial! A dishwasher has a built-in safety feature: the heating element can only activate when there is sufficient water pressure (otherwise, it burns out immediately). If your filters at the bottom are full of grease or food residues, the water cannot circulate quickly enough. The machine registers too little pressure and simply refuses to heat for safety reasons.
The solution: Remove the filters, scrub them thoroughly with hot water and a bit of dish soap, and test if the machine heats up again on a short, hot programme.
2. A software 'glitch' (The hard reset)
Just like your computer or smartphone, the 'brain' of your dishwasher can sometimes freeze, causing the signal to heat not to be transmitted.
The solution: Perform a hard reset. Unplug the device (or turn off the fuse in the fuse box) and wait at least 15 minutes. Turn it back on and run a hot programme (e.g. 70°C). Is it still not heating up? Then there is definitely a faulty component.
When do you need a We.repair technician? 🔧
Is the water still ice cold, even after a reset and with clean filters? Then it's time to call in an expert. These components are usually responsible for the lack of heat:
Burnt-out heating element (Heat pump): This is the absolute number one cause. In modern dishwashers (such as Bosch and Siemens), the heating element is built into the circulation pump. If this element burns out, for example due to age or heavy limescale buildup, the water remains cold.
Faulty temperature sensor (NTC): This small sensor measures the water temperature. If it is faulty, it may incorrectly signal to the circuit board that the water is already 65 degrees, preventing the heating element from being activated.
Problem with the control module (Circuit board): Sometimes the heating element is perfectly fine, but the relay (the electronic switch) on the main circuit board has burnt out. The heat pump simply does not receive power.
Broken pressure switch: As explained with the filters, the machine needs to be sure that there is water inside. A faulty pressure sensor 'thinks' the machine is empty and blocks the heating.
Washing with cold water only wastes electricity and soap. Our experts safely measure the heating circuit and replace the faulty component, often right in your home. Schedule a repair with We.repair now.
💡 Behind the scenes: Where is that heating element actually located?
In the past, you would see a thick metal coil at the bottom of the dishwasher (or washing machine) that became glowing hot. You don't see that in modern dishwashers anymore. So how does it work?
Modern machines use a 'flow-through element'. This is a clever, compact cylinder that is directly attached to the circulation pump. The water is no longer heated while it stands still in the tub, but is heated 'on the fly' as it is pumped at high speed to the spray arms. This is much safer, saves a lot of space in the wash tub, and ensures that the water reaches the right temperature much faster and more energy-efficiently.
What does the error code on your display mean? (By brand) ⚠️
If your dishwasher does not heat the water, it often shows (but not always!) an error code at the end of the programme:
Bosch & Siemens: E09. This is the most notorious code for these brands and almost certainly indicates a burnt-out heat pump (heating element).You will need a technician for this.E11 (error with the temperature sensor) also occurs.
AEG, Electrolux & Zanussi: i60 or 6 flashes. This indicates an immediate heating problem (too slow or not heating at all).
Miele: F24 (heating relay defective) or F25 (desired temperature not reached).
Whirlpool & Bauknecht: F3 (or 3 flashes). Heating error.
Prevention is better than cure: 3 tips for a long lifespan 🛡️
The heating element is the hardest working part of your dishwasher. Here's how to prevent it from burning out prematurely:
1. Descale your machine (The silent killer) Limescale insulates. If a layer of limescale forms on the heating element, it can no longer transfer its heat to the water. The element then has to work harder and overheats, until it literally goes 'bang' and burns out. So make sure your salt reservoir is always filled (or descale the machine thoroughly twice a year).
2. Clean the machine regularly Run a programme at the highest temperature (at least 70°C) once a week and run a programme with an empty machine and a bottle of machine cleaner once a month. This dissolves the layers of grease that adhere to the temperature sensor (NTC). A 'blind' sensor causes malfunctions.
3. Don't leave long skewers lying around Hard, long objects that slip through the filter can block or damage the pump (where the element is located). Always scrape your plates well.
Repair or replace? (Honest advice) 💰
Because the fault often lies with the heat pump or the heating element, people often think the machine is ready for the scrap heap. But that's a shame!
Repairing is almost always the smartest choice. A new heat pump is a standard replacement part that a We.repair technician can replace relatively quickly. The cost of this is negligible compared to the purchase, delivery, and installation of a completely new dishwasher. If your appliance shows no other issues and is less than 10 years old, replacing the heating element is an excellent investment that breathes new life into your appliance.
Frequently asked questions about leaking dishwashers ❓
Everything you need to know before deciding to call a technician. These are the most googled questions about dishwashers that do not yield a clean result.
Your dishwasher does not use hot air to dry, but employs 'condensation drying'. At the end of the wash cycle, the machine rinses with scalding hot water (up to 70°C). The plates and glasses become so hot that the water evaporates on its own and condenses on the cold stainless steel walls of the machine. Without heat, there is no evaporation, and thus a soaking wet load.
Technically, it won't cause any harm, but we strongly advise against it. Cold water and dishwasher detergent do not dissolve the grease from your pots and plates. This grease solidifies in the drainage hoses of your machine and your kitchen, which will quickly lead to blockages and a terrible smell.
Make an appointment now
If you can’t find the error code or the tips above indicate that you can’t solve the problem yourself, you can immediately book an appointment so that a professional technician from We.repair can come to your home to repair your Miele washing machine