noisy Ferroli 77 FFboiler

My first post, hoping for some advice.
combi boiler Ferroli 77FF req to be topped up on regular basis.other problem is the boiler makes what i can only describe as a \\\"grinding noise\\\" on occasions,this when the CH is on,if i then turn on the hot water tap the noise stops and then starts as soon as tap turned off. I\\\'ve noticed that the pipe outside is getting some drips.If i then top the boiler up its ok for a few days then i get the grinding again when it runs alittle low.
Hope i\\\'ve made clear what the problem is, any comments or advice much appreciated,thanks in anticipation

smudge450 said:

I\\\'ve noticed that the pipe outside is getting some drips

i get the grinding again when it runs alittle low.

Click to expand...

Pressure Relief Valve is letting by then ...
Question is:- Is it passing water because its doing its job or because its knackered.
Remember I can only give an educated guess without seeing it. [You may or may not have a leak as well]
My guess is that it has been doing its job because theres a fault with your pressure vessel and now it may have taken your PRV with it. The grinding noise may mean that your pump is the next 'domino to topple' if you dont act quickly
Assuming the pressure is set to 1 - 1.5 bar when cold. Does it go over 2.5 - 3 bar when in use?
Its not uncommon for either a PV, PRV or both to go in an older ferroli like yours