If you own a Vaillant boiler and have encountered the Vaillant F75 fault, you’re not alone. This common error typically points to a water pressure detection issue. Understanding what causes the F75 fault and how to fix it can save you from unexpected heating disruptions.

At DAKS Plumbing, we provide expert heating services and plumbing solutions across Swanley, Dartford, Eynsford, Farningham, Hextable, West Kingsdown, Crockenhill, Wilmington, Orpington, Bexley and the wider Kent area.

What Does the Vaillant F75 Fault Code Mean?

The Vaillant F75 fault code signals that the boiler’s pressure sensor has failed to detect a pressure change when the pump starts running. This can be caused by:

• A faulty pressure sensor
• Airlocks in the system
• Debris or blockages in the pipework
• A failing boiler pump
• Low water pressure in the system

How to Fix the Vaillant F75 Fault

1. Check the System Pressure

Low water pressure is a common cause of the Vaillant F75 fault. If your boiler’s gauge is below 1.0 bar, you may need to repressurise the system.

How to repressurise your boiler:

• Locate the filling loop (usually a silver braided hose beneath the boiler).
• Slowly open the valves to allow water into the system.
• Once the pressure reaches 1.5 bar, close the valves.
• Reset the boiler.

2. Bleed Your Radiators

Trapped air prevents proper circulation and may trigger the F75 fault. Use a radiator key to bleed air and restore efficiency.

3. Inspect the Pressure Sensor

Pressure sensors can clog with dirt or debris. Cleaning or replacing the sensor often resolves the problem. For peace of mind, book our leak detection service to identify any hidden issues.

4. Check for Blockages

Sludge buildup in the system can cause pressure issues. A power flushing service clears out blockages and restores full efficiency.

5. Contact a Professional Heating Engineer

If the Vaillant F75 fault code persists, call a Gas Safe engineer. DAKS Plumbing provides reliable boiler repair services in Kent to get your system back on track.

Preventing Future F75 Faults

• Book annual servicing with a qualified engineer.
• Clean the pressure sensor regularly.
• Check for leaks and fix them promptly.
• Schedule power flushing to remove sludge and debris.

Preventative maintenance saves money and reduces the risk of breakdowns.

Get Expert Help from DAKS Plumbing

If your Vaillant boiler is showing the F75 fault code, don’t ignore it. Contact DAKS Plumbing for professional support across Swanley, Dartford, Orpington, Bexley and the wider Kent area.

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