Strange Home Radiator blockage

[A100man]

I've been cleaning my rads out one by one and the last one I took into the garden for the hose treatment was blocked solid with some weird white chalky substance. Not hard like limescale but softer like school chalk. I removed the rad tails and rodded it all out but I'm confused how it got there. Horrid 'black as your hat' treacle in the other rads but not this stuff. Biggest piece I extracted was teh size of a broad bean - half the lower 'rail' of a 1.5m radiator was solid with it.
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Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[Andy Perrett]

Lowest point of the system?

I have one where the to and from pipes originate from the floor above.
It does similar.

[A100man]

[Freddyfruitba...]

Could it be plumber's mait, applied over-enthusiastically by the original system installer?
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KC100->CB100N->CB250RS--------->DL650AL2->R1200RS->R1250RS

[A100man]

[RhynoCZ]

Have you checked the water/heating medium, yet? Hard water causes limescale.

There are test kits for hard water, limescale inhibitors etc. If you used your tap water as your heating medium, then there should be other tell tale sings all over your house (kettle, boiler, the faucets...)
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'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[JackButler]

At a guess it's rust inhibitor, either poorly added to the system or by bad luck it's collected there & coagulated.

Once found a layer of the stuff on top of an open feeder tank which could only be described as 'lard'.
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I clean my guns with the tears of the snivelling, left wing scum.

[A100man]

[A100man]

Showed some of the pieces my time-served heating man and he'd never seen it before either!

Oh well all back together with new valves and it's heating up nicely again.
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Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[MCN]

Did you take a sample and test it.
Leave it for a day or so to see if it tries hard.
Wipe it on a piece of paper, let it dry, Hold it up to a light and check if the paper is 'sorta' transparent-ish (grease/fat/oil test.).

Test it for flammability. (Justfuckinaboot)

Fernox have a heating water sample service.


https://fernox.com/product/system-health-check/

Do your duty and get it done.
BCF massive needs to knows now.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[A100man]

[Robby]

Sounds like leak stopper. Looks like PVA glue going into the system, it's meant to only harden on contact with air.

Like any leak stop stuff (home or vehicle) it's an ugly bodge.

[MCN]