Vaillant Ecomax losing preasure

[kxt308]

My mum's boiler has been losing preasure for the past 3 days. Re-pressurise system every day and only lasts for approx 24 hours.

I think the expansion vessel may be faulty.

As i may have to replace the EV do I need to add an inhibitor liquid, if so how do i go about it.

Many thanks

 

[gas4you]

Have you tested the EV?

Follow instructions in FAQ's to check it.

Have you checked the prv discharge pipe outside isn't dripping? Have you checked for leaks on the ch system?

If not pressurise boiler, isolate ch by shutting ch valves under boiler, then leave as long as possible. If no pressure loss then leak is on system.

You can still use the boiler as a water heater whilst ch is isolated.