Search for your job
cv-ketel cv-onderhoud water

No hot water, but only heating

Wednesday 10 March 2021

It is an annoying problem when something turns out to be wrong with your central heating boiler. Very often, you notice that something is wrong with this boiler when you either have no water pressure or when you cannot get hot water from the tap. A common problem is that your heating works, but that you can't get hot water from the tap. Although this problem is less common than the problem where both your heating does not work properly and there is no hot water from the tap, having no hot water but heating does is not an unknown problem. It is not always necessary to call in a technician. Problems can often be found and solved by yourself.

No hot water

Let's first try to find out the reason that there is no hot water. There are different types of boilers. Although there is a difference in the various types, the operation of these boilers can often be compared. The parts in a boiler are related to each other. Therefore, it is important to check all the parts. By doing this, it is easier to exclude the possible causes of the problem. What you should definitely check is whether there is a power supply. A boiler always runs on electricity, and although it seems obvious that the power supply is always in order, this is not always the case. It could be that the plug is not in the socket, or that the appliance is not switched on. It certainly doesn't hurt to check this carefully, because it sometimes happens while doing odd jobs that people remove the plug from the boiler only to forget to put it back again. If the plug is simply placed in the socket, then you can continue with your analysis. Maybe there is no good contact in the central heating boiler. If so, you should reset it once to see if this fixes the problem.

The water pressure

As soon as it appears that the power supply is good and the plug has been properly placed in the wall socket, we can look at the water pressure. Every central heating boiler has a water pressure. This pressure is important. It is not directly related to the temperature, but it is still an important part to check. Normally, the water pressure is between 1.5 and 2 bar. If the water pressure is lower than 1.2 bar, the boiler must be topped up to 1.8 bar. The boiler must then be vented. By carrying out this step, you can be sure that the boiler is working properly, because you will already have checked the basic components.

Hot water?

Very often, the problems with the hot water from the tap have been solved with the previous steps. When there is just hot water coming from the tap or sporadically, there might be something wrong with the three-way valve. This is a valve that controls the distribution of water to the radiators and the plate exchanger. If this valve is in the standard position, the water goes through the heat exchanger of the central heating cabinet and then to the radiators, after which it simply returns. When the hot water tap is subsequently opened, the computer of the central heating cabinet receives a signal about this. The three-way valve will change its position and the water will be sent to the plate exchanger. There the tap water will be heated and this warm water will flow out of the tap. The three-way valve therefore has an important function in ensuring that the water is heated. If there is a problem with this valve or if the signal is not passed on properly by the computer, it is possible that no hot water flows through the tap. This is not a problem that you can solve yourself, because it involves advanced technology that needs to be checked. It is always advisable to call in a technician so that the problem can be properly analysed and then fixed.