Took the plunge and bought a fan,working on the fact if it wasnt broken could keep as spare as it will go eventually.IT IS THE FAN YAHOO!!!
Just thought i would update to help others.
Use to work in industrial heating wiring boiler houses,and had to do service when quite,so no numptey.That was when u could if you were capable,so combustion chamber not an issue.just felt it would still make a noise when starting if it was blocked?
Hello i have the above boiler,the supply fan makes a loud vibrating noise when slowing down,its very quiet when running and speeding up.so dont think fan or bearings,cleaned out condens trap and heat exchanger.still as bad.
any ideas? thanks in advance..