Central Heating Boiler was making noise and the engineer was called in.
He says that the boiler has scales settled at the bottom and when they
are disturbed it makes noise. Boiler has overhead tank.
What about putting this descaling solution and leaving it for some time
Let me hear your advice please. Also, its E Thorn timer has gone. I
understand it is a unit you just take it off and replace it. Any
experience on this topic please?