Vailant 630 System boiler hammer sounds

[arh]

Hi
I have a valiant 630 System boiler which is 18 months old. When it is on there are load hammer like sounds coming from it. When this happens you can see the pressure needle moving. It sounds like there is air in the system
Can anyone advise the best way to resolve this?
One or twice I hae seen F75 error on the bolier and switching it off an on has cleared it. Is this related?
Thanks.

 

[gas4you]

Sounds like a circulation problem, lack of it.

Although F75 is a known design fault with these boilers, it can also be caused by muck in the system, blocking it, which would coincide with the banging noises.

Was the boiler fitted to a new CH system, or was it a replacement boiler only and if it was, was the system fully flushed and cleansed, preferably with a power flush machine?

 

[arh]

The bolier was fitted to a new system as all pipework was changed. 3 of the rads out of 13 are old as they were only 2 years old. A power flush did not take place.

 

[Deleted member 105431]

is it over-rated? enter the diagnostics and downrate to 22kw and see what difference that makes (or call vaillant-you have a 2yr warranty)

 

[arh]

Can someone explain how to get into the diags menu?
My plumber over the phone suggested that an automatice air valve of some sort would solve the problem if fitted in line with the zone valve. Is this correct?

 

[Deleted member 105431]

Can someone explain how to get into the diags menu?
My plumber over the phone suggested that an automatice air valve of some sort would solve the problem if fitted in line with the zone valve. Is this correct?

press the i and + buttons simultaneously. d 0 will be displayed-press the i button again and a number (prob 30) will be displayed. using the - button lower this number to 20 then press and hold i until number stops flashing.

 

[Deleted member 105431]

I would also be looking at the pump. It's still under warranty so why not call Vaillant?

 

[arh]

Vaillant visited today and replaced the pressure sensor. Also topped up pressure in expansion vessel. Boiler seems to have stabilised. Hopefully the problem is solved.