Potterton Promax SL 15

[greengrass]

Supplied and installed by British Gas 7th Oct 2010, Potterton Promax SL 15 fan assisted condensing boiler 1yr 10days old. Noise developes on fire up sounds like bumble bee stuck in the system.

Engineer from British gas homecare came on 13th last week decided it needed new fan as he could see no other reason for the noise although said the pipes were vibrating when the noise started with casing off, fitted new fan on the 14th, and on fire up in evening the noise worse first the buzzing then follows on with tapping noise like the old cars valve tappets or small end piston bearing tapping lasting around 4 mins then settled down to a normal level what one would expect. What's the possible cause?.


The other point the engineer noted was the header tank water is dirty yet when the boiler was fitted it should have had a powerclean for which we were charged £80 so I am assuming this was overlooked.
Maybe wrong but how is a powerclean carried out which I believe manufacturers insist on for each new boiler installation re-their warranty cover. One thing nearly forgot it runs 11 radiators, plus of course the hotwater sytem. 3 new type and the rest the old thinner ribbed type 3 are doubles,