Boiler pressure very high and pipe from boiler dripping outside

[Slackerpop]

Hi, hoping someone might be able to provide some guidance here.

Moved into a property a few months back and have recently noticed that the boiler pressure is regularly going up to over 4 when the heating/hot water is on and it then seems to stay that high until I bleed a radiator to bring it down.

There is also a pipe from the boiler area to outside that constantly drips a green-ish liquid onto the extension roof when the boiler is in use (Small black pipe in the photo) I’m a little concerned as there’s a huge damp patch on that roof now and I don’t know how long this has been happening for.

The boiler is due a service but there’s a 2 month wait if we go with the company that the previous owners used.

Is this a serious problem and should I be getting someone out urgently? And am I doing any harm by regularly bleeding a radiator to bring the pressure down?

Any suggestions or thoughts would be greatly appreciated!!

 

[Wayners]

Expansion vessel needs pressure or is leaking. Will only get worse so don't leave it. Get a plumber.

Pressure release valve leaking