how much water in central heating system?

mrs_baggins

I know this is a 'how long is a piece of string' question but I am wanting to drain and clean my system and as I am on a dreaded water meter want an indictaion of how much its likely to be. I have open vented system (i think)- stored hot water not combi. And about 12 radiators.

ValHaller

The water will cost you significantly less than £1 for the indirect part of the system. It is not normal to drain down the direct stored hot water part of the system for cleaning. Even if you drained down the direct part, you would probably get that within your £1

diywhynot

Guesstimate 12 or so flushes of a loo but depends on size of rads.

HappyMJ

mrs_baggins wrote: »

I know this is a 'how long is a piece of string' question but I am wanting to drain and clean my system and as I am on a dreaded water meter want an indictaion of how much its likely to be. I have open vented system (i think)- stored hot water not combi. And about 12 radiators.

About the same as a bath....maybe 100 litres....probably much less.

southcoastrgi

if you are putting cleaning chemicals in then these need to be flushed out which will prob take 3 or 4 complete changes of water, just emptying & re-filling with water isn't really going to do much to help your system

what probs are you having with it ?

macman

If it is badly sludged, the gain in efficiency you get will far outweigh the cost of the water used.

mrs_baggins

sorry for delay in getting back. I am not really having any cold rads etc but just replacing a couple of them so thought i wd take oppurtunity to clean the whole thing out. I know it will take a couple of flushes but just wondered about the amount of water in total. If its a bathful its something i will just have to get on and do!

macman

I appreciate that this is MSE, but aren't you getting this a little out of proportion? If your bath is (wild guess) 1 cubic metre, then the cost of that even in the most expensive region of the UK (SWW) is about £1.95.
If the flushing work makes your boiler and CH just 1% more efficient, then on a typical dual fuel tariff of £1,250, you'll still save 6 times more on gas than you'll spend on water.

Mr_Ted

mrs_baggins wrote: »

I know this is a 'how long is a piece of string' question but I am wanting to drain and clean my system and as I am on a dreaded water meter want an indictaion of how much its likely to be. I have open vented system (i think)- stored hot water not combi. And about 12 radiators.

Yes totally how long is a piece of string?
Dependant on many factors, system size and type, pipework size, boiler size and type................?

Why do you need to clean the system?
If you dont have sludge problems the more fresh water you put into the system the more possibility you will get sludge produced!
If your worried about cost of water just refill the new rads only when installed and add an inhibitor to the F&E tank prior to refilling?