Old, under-used CH system. Flush or not?

My elderly mother runs her conventional CH system only when the weather is cold and only in the room(s) she is using. This means that a lot of the radiators have no water flowing in them most of the time. I think that one of the rads has developed a pinhole leak and a local plumber has isolated it by shutting the valves at each end.

What should we do next? I was considering flushing the system with X400 but this will probably make it worse, right? Should I bung in some X100 to prevent it getting any worse or will it just bind to the water and sludge in the system?

Would the best plan be to wait until the weather warms up, flush everything with clean water, look for leaks and replace the damaged radiators?

If radiators are pinholing they need to be replaced. Once that's done you can think about flushing the system and adding the correct amount of inhibitor

Thanks. -Should we replace them all or just the one that leaks? Are they all likely to fail around the same time?

Go and take a good look and replace dodgy ones then flush.Bob

Before you do anything you should take a sample of rad water in a large glass and see what colour that is.

A photo here and we can all give our views on what the problem is.

A properly operated system should never pin hole rads.

It may well indicate a fault and worse that problem may well be brought by her turning most off and causing a problem.

Tony

It may be that your mum doesn't use all of the rads in her home.

However, the ones she does use, and the domestic hot water, are all part of a system, and this needs to be maintained to a suitable standard, to ensure continued trouble-free operation.

When it does eventually fail, and it will, you can bet it'll be during the coldest time of year and your mum will not enjoy being without CH and HW!

You could isolate all the rads and give the pipework a flush through with clean water (what system does she have?) and then open and flush one rad at a time, with old towels and buckets on standby in case one blows. Then systematically replace as necessary.

Remember that 'all' rooms should have some heat going into them, even if low level and only occasionally, to prevent other issues such as damp and condensation.

If TRVs are not on the system, put them in and have them set to low in the least used rooms.

Consider the outlay as an investment in the property and not just for your mum's current use of it.

Thanks, Guys.

I'll have a good look, replace the leaking one(s), fit TRVs, flush and inhibit. (I might need some professional help...) "Hi Ma, welcome to the 21st Century..!"

@dilalio I agree with what you say - now I just need to persuade her that turning things off doesn't always save money. Her system is open vented and pumped with a conventional non-condensing boiler in a 3 bed detached house. I don't think it's been serviced for a while and certainly not since Dad died (18 months). She lives on her own with a bottle of cheap brandy and Sky TV and woe betide anyone trying to tell he that she "should be doing it like this.."!! Unfortunately, she's over 80 miles from me and I have a young family. But you can't help with my personal tribulations - sorry!

Thanks again for the clear advice.