Changing Radiator - Clean and Flush

bigfoot371

So I came home to find my boiler had lost all pressure and cut out.

I have a smallish leak under one of my radiators. In the last hour I've had about 20ml come out. It's coming from near the valve, but looks like its coming from the rusty patch...


So I've ordered a new radiator of the same size and a drain off valve to fit on the pipe.

I can't find a drain off valve anywhere and this is my only radiator downstairs.

I'm a newbie homeowner... and a newbie DIY have-a-go hero so bear with:

- I assume I can isolate the Radiator, drain into a bucket and crack off one side and drain into a bucket.

- Then open exposed valve with a bucket (and old towels) under and start cracking open the upstairs bleed valves. I have no hosepipe/fittings to fit 1/2in BSP female and not really anywhere to drain to that side of the house. Buckets will do and chuck in outside drain.

-Then replace the valves (One thermostat and one isolator with a drain off to side). Fit the radiator hoping not to damage the copper brazed joints under the floor when jiggling and slightly bending pipes to reach (I can't braze, or lift the laminate floor to check).

-Chuck in a bottle of cleaner (or 1/3th as I estimate only 100l in my system - I'll count the buckets as I empty, it's only 2 large and 2 v small rads in the system) (it's an old house, may as well do this while I need to top up inhibitor anyway) and pressurise the system, bleeding downstairs then upstairs. Would I need to fill/bleed/fill/bleed in a few goes? Can I leave the fill tap on and run around closing off the bleed valves as they fill?

-Week later drain the system (from my swanky new drain off valve), fill up and stick some inhibitor in the upstiars radiator.

-Am I best filling and draining a couple of times with normal water until it runs clear?

Hope someone can advise, I'm a different sort of engineer and this seems logical to me and relatively straight forward. Don't think sediment is a bit issue (no noises) so don't see value of a powerflush I don't have the cash for. As two rads have rust I think a clean is worth it.

Thanks

Bigfoot, AKA not Tommy Walsh or anyone generally competent at manual labour.

thescouselander

You might not need to drain the system for this job. If you can isolate the boiler at the feed and return (sometimes there's valves on the boiler for this) you should be able to take the valves off one at a time without the water coming out.

bigfoot371

Is it not worth flushing anyway? Surely the head pressure on the exit side of the Rad would cause a large loss of water when the isolating valve is taken off?

Ruski

Yes, as soon as you have two exits in a system the vacuum will release and you'll be glad you did it your way instead!

What you're planning is fine - if you can rig up your 3/4 to a hosepipe and run it outside it will be so much easier tho.

Good luck

Russ

Grenage

Your plan sounds good; don't be surprised if the water doesn't run completely clear after a couple of empties. I'd do as you suggested.