Noises from my Ariston Eurotherm Combi

[GrahamF]

When I turn on my Ariston Eurotherm, the boiler and connected pipes starts to vibrate and it makes a terrible rattling noise. Loads of water also comes out from the outside hot water outlet pipe. However, when I turn a tap on full, the noise stops. Is the pressure in the system too high? The controller on the front doesn't seem to control the pressure which shoots up to 3 bar and the temperature to 60C - is this normal?
Any help apprieciated.

 

[ChrisR]

Sounds like you pump has packed up so everything boils. Check by removing its centre screw and poking screwdriver in (dribbles a bit). Try it with the HW on first!