Replacing radiators with 10mm pipes

u0362565 · Mar 1, 2016

Hi all,

I have double panel single convector radiators in my flat which are fine. They're cold at the bottom which i know normally means a sludge build up. Would getting someone in to flush them with chemicals work to clear this? And is that the only option apart from replacing the radiators altogether!? Are there any approaches i could attempt myself?

The supply pipes are around 10mm diameter so not sure if thats compatible with new radiators?

Meady · Mar 1, 2016

The 10mm pipe will be fine for new radiators. How old is the system?

Best · Mar 1, 2016

If the rads are sludged and you want to save money you could drain the system and remove rads one by one and flush them, but unless you are on a ground floor flat you would have a problem.
The 10mm pipes supplying one rad are okay if not too long to each rad, unless they are sludged also.
Circulating pumps can also be blocked or faulty.

u0362565 · Mar 1, 2016

The boiler is roughly 5yrs old but the pipework and radiators are older i believe. We're a couple of floors up so i'd rather avoid detaching each radiator and flushing unfortunately. Thats why i wondered if it would be easier to just replace them with new. I was under the impression that the whole under floor pipework was 10mm diameter from the boiler although having said that i can't see any 10mm pipes leaving the boiler i don't think but haven't looked too closely.

Thanks

Best · Mar 2, 2016

It is hard for me to say without knowing how badly sludged up the rads are. Age doesn't matter because it depends how fast or slow corrosion occurs in a system design and its history and also if inhibitor was added. But to pay £500 for a power flush might be foolish if rads are well corroded and certainly not worth it if only a few inexpensive rads. If existing rads are a bit tired looking, needing painted etc and maybe not perfect for heat output, new rads will look well and might give better performance.
The 10mm pipes to each rad will either come directly teed off from large pipes, or manifolds will be somewhere doing same.

u0362565 · Mar 2, 2016

Yes hard to determine the level of corrosion, from the outside at least the rads are in reasonable condition with paint only starting to flake on parts of one or two. They'll have been painted within the last few years i suspect. There's only 6 rads in the flat and only have 5 turned on. Probably wouldn't be a hell of a lot more to replace them if flushing could be £500.

Thanks for the advice.

Gary80gas · Mar 5, 2016

Add a system cleaner, drain and refill. If no better replace rads and add inhibitor so no repeat of problems. If the rads are really old just replace them, the new ones will work and look so much better.

u0362565 · Mar 5, 2016

Is that something I could do myself easily? I'm in a block of flats on 2nd floor so any leaks will havw consequences. Is it easy to drain the system, it's presumably pumped out somehow? I don't have a drain valve on any of my radiators that I can see.