unvented boiler flush

[TryAgain2]

Hi
I have an unvented hot water system that has a circulating pump. I suspected the pump had broken and have just changed it. When I took the pump out it was impressively blocked with hard 'lime scale like' crud. I scraped out the ends of the isolating valves but I guess some of the crud is now in the tank - perhaps along with much more.
My question is do I do nothing? Should I flush the hot water cylinder? how would I know if it was half full of sludge? If flushing is advisable is it a DIY job?
As it is a hot water system I guess you cannot use inhibitors or flushes like you might on a radiator hot water system.
Thanks for any help offered

 

[Agile]

Not usually worth bothering.

If thats a secondary circulation pump you may not have needed it anyway.

They are best on a timer to only operate when needed.

On a pump limescale can be dissolved by HCl.

Dont use it on anything ali or copper though.

Most of Devon is soft water though! Hard igneous rocks!

Tony

 

[JohnD]

If you get a water softener, then as well as not making any new limescale, it will slowly dissolve what is already there.

 

[TryAgain2]

Thanks very much both of you. The pump does seem to help as the house is long and thin (sadly not a lovely Devon longhouse) and the boiler is at one end.

 

[Agile]

Where exacttly are you?

Are you sure the water is really very hard?

Tony