Hi, we got the above boiler fitted around 3 years ago. It makes a loud buzzing noise when CH is on. It does not do it when HW is on, in fact the noise goes away when you run the tap and comes back when it is turned off again. I got Homeserve out last year and the damn thing didn't do it while he was here! Got them out again last week and he reckons it is a blockage in the heat exchanger causing the noise, but we aren't covered for cleaning it out. He reckoned to get some X100 (?) and run the system with it in for a month, drain it, refill with water only and run, drain again and refill with inhibitor added. Sounds good to me. The problem is that since he has been the water pressure keeps going up to the 3 bar mark and going into fault mode with the code saying 'no water pressure'. I have drained some water out of the system 3 times now, each time taking the (hot) system pressure down to around 2.4 bar. The next day the pressure goes back up to the alarm point again!
Now, is this a symtem of the blockage in the heat exch. or possibly a passing top up valve? It hasn't done it before. We have had to top the pressure up slightly every now and again but not often, and I only take it up to about 1.5 bar when I have done it.
Also, is there a better method of cleaning the exchanger than running with X100 in for a month?
Now, is this a symtem of the blockage in the heat exch. or possibly a passing top up valve? It hasn't done it before. We have had to top the pressure up slightly every now and again but not often, and I only take it up to about 1.5 bar when I have done it.
Also, is there a better method of cleaning the exchanger than running with X100 in for a month?
