Vaillant F75 and F22 Error Codes

Vaillant F75 Error Code

If you are staring at an F75 error code on your Vaillant boiler, it indicates a water pressure issue within the system. Let’s break down what the F75 error means and what you can do about it. The F75 code happens when the boiler is not detecting an expected rise in pressure when the pump turns on. This pressure increase is crucial for the boiler to function properly. There are three main reasons why this happens:

  • Faulty Pressure Sensor: This monitors the water pressure in the system. If it is not working it won’t send the correct signal to the boiler, triggering the F75 error.
  • Faulty Pump: The pump circulates water throughout the system so if it is working correctly, it will create a change in pressure.
  • Low Water Pressure: If there is simply not enough water in the system for the pump to function effectively this can also be a cause.

Before you call an engineer you might consider these first:

  • Check the pressure gauge: Consult your boiler manual for the ideal pressure range. If it is low, you might be able to top the water up following the manufacturer’s instructions. However, stop and call an engineer if there are visible water leaks.
  • Restart the boiler: Sometimes a reset can resolve odd glitches. Refer to the Vaillant manual for your model.

Vaillant F22 Error Code

An F22 error code on your Vaillant boiler signifies a drop in water pressure below the amount needed for the boiler to function. Several factors can contribute to an F22 error:

Lack of Water: This might seem obvious, but sometimes the system simply lacks enough water. Check your boiler’s manual for the proper filling procedure.
Air in the System: Air pockets can disrupt pressure readings. This is a common occurrence, and you may need to bleed the radiators to release trapped air.
Leaks: A hidden leak in the pipework can cause a gradual or sudden pressure loss.
Faulty Components: The pressure sensor or expansion vessel could be malfunctioning, leading to inaccurate readings or pressure inconsistencies.

Whilst topping up the pressure might seem like a simple fix, keep an eye on the pressure gauge at the front of the boiler for next few days to see if the pressure is holding.

It is advisable to call a Gas Safe registered engineer if you have been unable to deal with this simply as a top up to ensure that any underlying issue is correctly fixed.