The dirt that came out from my radiator!

pieroabcd

Hi, 
as I wrote other times in the past my radiator at the second floor got hot only at the top, while the bottom remained cold.
Today I've finally cleaned it in the shower, with hot water and using a game of pipes, making water flow in both directions, up and down, for something like an hour.
The stuff that came out is incredible! Dirt like carbon powder in huge amounts. Only at the end there was some residue of dust.
This radiator must have been installed in 2011 and it's a modern 2 columns radiator, not some relic of the bad old times.
How come that so much dirt has accumulated only at the second floor?
Is there anything that I can do to prevent more dirt to build up in the future? Cleaning a radiator like this is not a game.

I've also replaced one of the taps with a Dreyton RT212 TRV and to my surprise the pipe that connects the valve with the sensor to the entrance of the radiator has threading only towards the radiator, while the other end that enters in the valve relies only on an olive. I've installed it, but is it reliable? It doesn't make me feel relaxed because I'm afraid that it might leak.

Thanks.

Lorian

Do you have a magnetic filter in the system, and Inhibitor fluid added?

WIAWSNB

Do you want the good news or the bad?
Good? Ok. It ain't dirt.
Er, bad? It's corrosion. Your rads are rotting from the inside-out.
Why did it happen? Likely because corrosion inhibitor wasn't added to the system water, possibly at the install, or possibly the water was replaced later?
Possibly that rad has 'collected' most of the sludge being created in the whole system, and the other rads aren't too bad. 
I'm guessing you don't have a magnetic filter fitted? Worth doing, along with a dose of system cleaner.

WIAWSNB

Pic of the rad connection you are asking about? 
But, most final connections to the rad are, indeed, screwed, often with a slight taper. All it needs is either a smear of jointing compound, or a few wraps of PTFE tape.

pieroabcd

I don't really know if there's a magnetic filter. How can I find out and where does it have to be added?
If I wanted to add a corrosion inhibitor now, what shoud I do?
As for the corrosion, is it corroding the internals of the radiator or can it even affect the flow and return pipes?

WIAWSNB

If it's iron oxide 'sludge', then it's corrosion from the insides of the steel radiators. The pipes are copper, and usually immune to corrosion. 
Mag filters are usually fitted on the Return pipe, and usually just before the boiler, and they catch this oxide. Could you take some photos of your boiler and pipework?
Does your boiler have a pressure gauge?
Sludge can certainly affect pipes by coating them, especially if there are low runs under the floor. Usually, tho', it's more obvious in the rads themselves, where it builds in a pyramid shape in the middle, making it cold along there.
And, yes, it can also affect your boiler, especially if it's a combi - it tends to block the P2P exchanger.
Anyhoo, photos, please. 
Are you able to remove your rads one at a time and repeat this process? And can you do basic plumbing - cut a pipe and insert a filter? If so, you can sort this yourself, and save many £undreds.

Albermarle

If I wanted to add a corrosion inhibitor now, what shoud I do.

It can depend on your set up.
There are plenty of You Tube videos on what to do.

If you have a towel rail type tall radiator in a bathroom, there a pretty easy method.
You turn  off the inlet valve/TRV. Then unscrew the inlet nut  at the top of the radiator ( usually contains the bleed valve).
Then unscrew the outlet valve a couple of turns and catch the water as it comes out up to about a litre. Have old towels ready !
Screw the outlet valve back up, and add inhibitor through the inlet at the top. 
Top up with water.
Screw the  nut at the top back in, and open the inlet valve and turn the heating on and check for leaks.
Bleed the radiator.

pieroabcd

I like it! Thanks

pieroabcd

This is the TRV.
My concern is that the end of the pipe that fits in the threading of the valve is smooth, not threaded. There's only the olive to prevent leaks, that doesn't look that great.
Did it cost so much to add threading on both ends, like in all other TRVs?

WIAWSNB

pieroabcd said:

This is the TRV.
My concern is that the end of the pipe that fits in the threading of the valve is smooth, not threaded. There's only the olive to prevent leaks, that doesn't look that great.
Did it cost so much to add threading on both ends, like in all other TRVs?

It's a 'compression' fitting, and a standard plumbing jointing method. No risk. (And if both ends were threaded, how would you arrive at the valve being vertical?)

The threaded end that goes into the rad is the one that needs either jointing compound - a smear - or PTFE tape.

Anyhoo, find out if you have a mag filter, and I'd strongly suggest you fit one of these first. It'll have the added benefit of making it easy to add the chemicals as required. 

WIAWSNB

If you can, leave the existing threaded spigot in place, and reuse it with your new valve. Just add that smear of compound to the olive and thread.