Worcester Bosch 24i junior clanging noise on CH mode

Hi

Have the standard Worcester Bosch 24i junior (about 4 years old). Both the DHW and CH been working fine for the last 4 weeks or so but yesterday when i put the central heating on it made a very loud clanging noise as if stones where being churned in the boiler itself. It then switches off. Have restarted it both from mains and the reset button but still get the same noise and problem. Hot water seems to be working perfectly fine. I have bled the rads and also drained the boiler and re filled it back up to 2 bar to see if it corrects the problem - but this hasn't solved the fault/problem.

I would appeciate any suggestions on what it could be and course of remedy.

Cheers
Sam

Check to see if pump is turning!

See FAQ on this site.

Tony

(Thanks for replying Tony)

Anyone else had this problem or can offer an insight as to what it may be?

(Is this boiler still available as ive just had the kitchen done up with a bespoke housing for this boiler. Or any suggestions for something of similar dimensions.)

Thanks!