What does f75 mean on a vaillant boiler?

The Vaillant Group is one of the leading and a reputed brand in the boilers global market. The company is dedicated to provide true, long-lasting and comfort to all the homes across the UK. That’s why there boiler comes with 10 years guarantee, becoming the most reliable boilers in the market.

But in some of the Vaillant boiler there is f75 code which appears on the display of the boilers. You might be thinking what does f75 mean on a vaillant boiler?

Here is the answer to your question

The Vaillant f75 error is a common fault code on Vaillant ecoTEC boilers. Vaillant ecoTEC is one of the most leading ranges of boilers. The early models were fitted with a pump and a pressure sensor was not so reliable. In the same period, 2000-2010 EcoTEC models were launched and often experienced f75 fault code.

However, before the Vaillant Company was getting there pumps manufactured from a company called Wilo. Those pumps are now having a high failure rate. And they are likely to cause leakage and spillage. But now, the Vaillant is using the pumps manufactured from Grundfos Company, which are far better than that of Wilo Company.

What is the f75 fault code?

To the answer of your question what does f75 mean on a vaillant boiler? We have some details which will make you understand about the fault.

According to the Vaillant Installation and Service Book, the f75 fault code signifies ‘Fault, no pressure change detection when starting-pump.’

How the f75 fault code is caused?

The Vaillant f75 fault code is caused mainly by two reasons:

1. A faulty pump
2. A clogged pressure sensor

The fault is either because the pump of the boiler is not working properly or the pressure sensor is congested in debris and unable to find any kind of change in pressure even after the pump is working properly.

How to detect f75 default in the boiler?

After getting to know about what does f75 mean on a vaillant boiler? You might be thinking how you will get to know that the boiler has been affected by the f75 default.

Not to worry it following these steps will let you know about the fault code.

Start by checking the pump

The easiest ad quick way to diagnose the f75 fault code in the boiler is to check the pump. For this you need to follow some steps.

1. Firstly, you need to reset your boiler. This can be done by switching the lockout button which is signified with a flame symbol.
2. Now, wait for few minutes and start to run the hot water tap. This will fire the boiler.
3. As soon as the boiler begins to fire, the heating pump will knock in and will supply the water to the hot water tap.
4. If the pump is not in a working condition , you won’t hear any sound nor will feel anything. If this happens with your boiler, you need to call a gas safe engineer who will install the replacement pump for you. Hence you will get to know the fault f75 has been caused because of the faulty pump of your boiler.
5. Whereas, if the pump is working you will get to hear a humming sound and the boiler will start to vibrate softly. The pump will begin and makes sound for about 20 seconds and afterwards gets silent, then resound again. If you can hear the sound of the pump, this will ensure you that your pump is working properly and the fault is due to the pressure sensor.

How to fix the Vaillant f75 fault?

If the fault is caused due to the pressure sensor than it can be healed by stripping it out and cleaning the water block where it is fitted before installing the new one. You need to remember this, that the pressure sensors are comparatively inexpensive. So try to replace them instead of making them clean and refitted again.

Prevention tip

The sludge is said to be the major cause for the f75 fault code. You should make sure that the system is free from any contaminants. Also make sure that the inhibitor level are topped up to the correct and right level, this will minimize the emergence of the sludge. One more way to prevent the sludge from reaching the boiler and its components is to install magnetic or dirt filters involved in it.