Note of caution
Always remember to cut the power and water supply to the dishwasher before doing any tinkering.
Cause 1:
The cause for your dishwasher not heating properly is because its heating element has probably burned out.
Solution:
One possibility is that the heater is so broken that it is visibly damaged or broken, or that it is blistering. To this end, you will only require to disassemble your dishwasher; if you don’t know how to do it, check this video for a great step-by-step explanation of how to do it.
However, it is not always obvious whether it is broken since the damage could only have occurred on the inside of the heating element. Thus, you will most likely have to conduct a ”continuity test”. For a more in-depth explanation of the testing process of your dishwasher, refer to the ”How to test it” section below.
Cause 2:
No hot water in the house/apartment.
Solution:
If your dishwasher doesn’t heat the water by itself and it requires a constant connection to a source of hot water, go and check said water source. If you are using a centralized heating system, see if there is any problem with the system’s ability to heat/pass the water.
The same goes for water heaters, with the addition of you having to make sure that the dishwasher is as close to it as possible. The longer the distance between the heater and the dishwasher is, the colder the water will be.
Cause 3:
A burned-out/damaged thermal fuse. It is important because, without it, the control panel would not receive any power and the dishwasher wouldn’t work.
Solution:
You will need to replace it. But before that, you should check if it still works by using a multimeter. Pull it out of the control panel (it is usually located on the top-side of the circuit board on the door) and give it the multimeter test. Set the multimeter on Rx1 and touch the fuses’ contacts with the multimeter probes. It should read 0 or around 0. If not, it needs a replacement.
Check this video for a nice step-by-step guide on how to access and replace it.
Cause 4:
A broken/damaged thermostat. It is an important component since it maintains the water temperature all throughout the heating cycle. If it is damaged or broken, it will not be able to ”tell” the dishwasher when to turn the heater on or off.
Solution:
Same as with the thermal fuse. In order to test it, you will have to follow the very same process as with the heating element. Furthermore, and fortunately, dishwasher thermostats are quite cheap to replace. Here is an example, although you will need to check on whether it is compatible with your washer. Check with the manufacturer for complete compatibility.
And here is a great video on how to replace the thermostat.
Cause 5:
Broken/burn out wires. This can range from pinched to being broken or burned.
Solution:
Repairs can simply be done by using wire connectors and wire strippers to remove wire insulation. If the wire is completely fried or otherwise unusable, use a wire cutter to cut it and then replace it with a healthy one. The main issue here is identifying which wires are faulty and which aren’t.
Here is a great video on how to work with wires, safely.
Will a dishwasher work without hot water?
The short answer is yes.
Most dishwashers are manufactured so as to take cold water from your water system and heat it up in order to clean the dishes. Furthermore, dishwashers are made to actually draw a small quantity of water for each cycle. Others depend on the water already being hot, not lukewarm, when it enters the dishwasher.
Continuing with this point, unless the water exceeds 150 degrees Fahrenheit, there is no risk to the dishwasher. And regardless of the issue, the dishwasher shall still take water, even if it is not heated/already hot.
The heating element
Thus, the problem does not lie with hot/cold water, but with the heating system itself. Or more likely, with the heating element, which in itself is responsible for heating up the water. If it is broken, the dishwasher will not heat the water and wash dishes as it should. The same principle goes with your house’s/apartment’s water heating.
However, that is not the end of the world. There are people who found out that their dishwashers didn’t heat water only after many uses. The problem with this is that, without hot water to properly wash the grease off plates, two things will happen.
How to know if you have a heating problem
The first is that your dishes won’t be properly washed, leaving the dishes not fully cleaned. Furthermore, greasy dishes that are not washed with hot water will have a harder time drying overall.
Secondly, and this is of greater concern, the interior of the dishwasher may get covered in grease; this is due to no hot water taking it down the drain with it which, in time, will have a few dire consequences on its health, such as:
- nasty greasy odors;
- clogged drain pipes;
- future uses will cover dishes/cutlery in bacteria or other residues.
So yes, they do work without hot water, but by doing so they skip over what makes them useful in the first place: washing dishes properly.
How do I know if my heating element is bad in my dishwasher
Many people have found out that their dishwasher does not work properly by simply looking at the dishes after the process. If so, ask yourself the following questions:
- Do the dishes not dry properly?
- Are they smelly?
- Are they a bit greasy?
- Are the sides of the dishwasher greasy or do they have
If so, you might have a problem with the heating element.
However, the best way of being sure that your dishwasher’s heating element is broken/damaged is by testing it for continuity (see ”How to test it”). This will undoubtedly show you whether it is broken by:
- By either you noticing that it is physically broken (damaged or has lumps on it); or
- By conducting the continuity test in order to see whether it still passes electricity to the dishwasher.
How to test it
The best way of testing whether the heating element of your dishwasher is broken or burned is by taking the continuity test.
Before anything can be done, make sure to individually remove the heating element from the dishwasher. After opening the dishwasher and taking out its heating system, you will need to undertake a continuity test. This test will allow you to see if there is a continuous path for electricity within the heating element.
This is crucial since it is what heats the water in the first place. If it has continuity, it will heat the water, but if not, and the electrical path is broken, the element is burned out and needs a replacement. Also, do not worry because of their appearance. DIshwasher heating elements come in many shapes and sizes, but they can all be tested in the same way.
Get a multimeter
For this, you will need a multimeter, either an analog or a digital model.
When using an analog model, you must first rotate the range selection dial to the lowest Ohm (Ω) resistance setting, which is usually on the bottom left.
Calibrate
Afterward, calibrate the multimeter, by pinching the probes together in a cross-like fashion. Then, by turning the cog on the left upwards, set the needle to read 0 (the utmost right).
Similar to the analog model, you must place it at the lowest Ohm (Ω) resistance value. If your multimeter has a value for resistance with tones (it looks like a volume icon), set it on that one instead.
Take the probe
Afterward, simply take one probe (the red and black cables attached to the multimeter) and then set them each to touch the element’s terminals. The terminals are the metal ending points of the heating element. Then, look at the multimeter.
If the meter shows a value between 0 and 50 Ohms (Ω) of resistance, then the element still has continuity. And if the needle does not move, or the display does not change significantly, there is no continuity. If so, the element is burned out and it requires a replacement.
For a more in-depth video regarding multiple issues, other than the continuity test, such as testing the thermostat, check this video.
Other reasons why the dishwasher is not heating the water
Other than the aforementioned possibilities, the main reason why your dishwasher will not heat up the water is simply that there is no hot water. Namely, if your dishwasher uses hot water directly and requires to be constantly connected to a hot water source.
In this case, see if there is something blocking your house’s/apartment’s intake of hot water. If your house/apartment has a water heater, check if there isn’t something faulty with the heater and that the dishwasher connects to it properly.