Overflow dripping from a combi boiler

I have recently moved to a new house where there is a combi boiler.

the overflow started to drip a few months ago and my central heating guy came round and put a new valve in. This stopped the dripping.

However, it has now come back again, albeit not as much as before.

The valve was a 2-bar valve. However, the pressure gaguge reads 2.5 ish. My central heating friend said that this should not cause the overglow to drip.

I cannot reduce the pressure by any means. How can I do this and is this the cause of the dripping?

Thanks for your help.

The dripping pipe is from the pressure relief valve ,they are usually 3bar.Your system pressure when cold should be between 1 and 1.5 and rise to around 2 ish. drop the pressure when cold useing the drain point (see boiler instructions often inside of lid ) DO NOT manually open the pressure releif valve or ot will never stop dripping (muck in valve seat ).allso check your top up loop/filling loop is disconected. ps what type of combi is it ?

The combi boiler is an ArisrelaeuroCombi SX 20 MFFICE.

Unfortunately the previous owner did not leave an instruction manual so I am at a loss to find where I can release the pressure.

Can you point me in the right direction of how to do this?

Thanks!

[Sorry, the make is:

ARISTON EuroCombi SX20MFFICE

you can release pressure by bleeding a radiator (takes a while)

Often after bleeding radiators you have to re pressurise the system, so you can releas pressure by bleeding