The f75 is a very common fault code with the Vaillant Ecotec boilers. The fault code comes from a pressure sensor in the boiler that does not notice a difference in pressure across the main heat exchanger! ( A lot of words i know! ) There are different reasons for this happening, firstly and the most common is a faulty pressure sensor, other problems that can cause the f75 fault code are blockages throughout the boiler restricting the water flow through the main heat exchanger to the sensor. A faulty pump is also another cause, if the pump isn’t running properly or is blocked then this will cause problems.
We are experts will Vaillant boilers, advise is free so please give us a call on 07585 660494.
