Central Heating long term water usage?

[Charles F]

Hi All,

A query re central heating long term maintenance. I replaced mine in its entirety about 10 years ago - it's a sealed system with new rads, mostly plastic pipework, and a new boiler about a year after that. It's had Fernox F1 added at the recommended concentration from the start, supplemented when needed, and has a magnetic filter on the return to the boiler - which doesn't collect much of anything. When I've needed to remove a rad the water is clear, and there is usually only a small amount of what looks like black iron oxide particles in the very bottom of the radiator.

My query is - do I just continue with an occasional extra bit of F1 added, or after ten years is it a good idea to drain, wash through with clean water, and refill with new F1?

Thanks,

Charles F

[Martin Brown]

Clean fresh water will come with a nice new supply of dissolved oxygen. I would leave well alone until you need to drain the system for some other reason. No point in spending extra money on Fernox unnecessarily.

[John Rumm]

With a nice clean system like yours, there will be no benefit in a drain and refill (unless you need to for other reasons).

Each time you refill you add fresh oxygenated water, and that will allow more corrosion - or at least mop up more of the oxygen scavenger in the corrosion inhibitor.

So basically, keep doing what you are doing.

[Dave Liquorice]

If it ain't broke, don't fix it!

[Charles F]

Thanks to all three respondents. It's what I'd hoped you'd say, does make sense - and for once is the easier of the options!

Charles F

[Dave Plowman (News)]

Not sure if water deteriorates with age? New is likely to contain things you don't want like oxygen and calcium.