Sludge remover and flushing

[candres]

Other than by professional power flushing can a CH system be cleaned out effectively?

Is there any difference in effectiveness between the various brands of standard CH sludge remover ranging in price from c £5 to £20 per litre?

Is it the case that normal flushing does not remove the black sludge from the bottoms of radiators and that removing radiators and pouring off the sludge is the only effective method?

I have a 20 year old open vented system with 8mm pipes at radiators and have just poured about a litre of black sludge from one radiator.

 

[mickyg]

A litre of sludge from one rad is bad news when you have microbore pipework(8mm pipes you describe). I would suggest taking some action rather rapidly...If its as bad as it sounds I would suggest firstly, removing each radiator and flushing it out with a hose in the garden. Once all the rads are cleaned out then use some cleanser, I always use sentinel X400, I've never tried cheap products and don't intend to. Stick to the big brands(sentinel, fernox,salamander) and you can at least know that its proven stuff. Just follow the instructions on the bottle. Leave it in for a few weeks and make sure it circulates round the rads as much as possible(You can leave heating on constant and turn off/down boiler stat).
A powerflush is the best most effective option if properly carried out, but these steps will be your best bet if its cost your worried about.

 

[Deleted member 105431]

like all chemicals they work better hot so make sure you run the heating everyday while they are in the system. . . . .

 

[candres]

Many thanks for your help, guys.
I may have overstated the first radiator sludge problem (more like a 1/2 pint!) but I checked another, smaller, radiator and got about 1/4 pint of reddish-brown sludge so I guess I do have a problem.
I'll bite the bullet and follow your advice regarding removal to flush with hose in the garden then, as I've usually done every three or four years, X400 for a few weeks with heating on, drain and flush and finally X100.
Not looking forward to lugging the 1400mm long ones through the house!

 

[andytheplumber]

Dont forget. When your moving these rads about the house, if the sludge spurts out the ends its like oil over your carpets. So tip them upside down and plug the outlets up with tissue or something. This sludge sticks to carpets like sht to a blanket.

 

[JohnD]

got about 1/4 pint of reddish-brown sludge so I guess I do have a problem.

indeed you do

reddish brown (rust) means that air is getting into your system which will rust away the radiators and boiler (steel + air + water) very quickly.

Find out where it is getting in, and fix it. You might have a leak, drawing in fresh water, or your system might be pumping over in the loft like a fountain and gathering dissolved air.

BTW if you filter your sludge and put it in a jar to dry, you will be surprised how little particulate volume there is in a pint of wet sludge.

 

[AlanE]

I'll bite the bullet and follow your advice regarding removal to flush with hose in the garden then, as I've usually done every three or four years, X400 for a few weeks with heating on, drain and flush and finally X100.

If you are PROPERLY flushing the system every 3/4 years and still getting this amount of sludge then there is something fundamentally wrong with your system.

 

[JohnD]

but did he put inhibitor in when refilling each time?

 

[candres]

Thanks for your further comments.

I have used inhibitor, usually X100.

I did discover very slight leaks, and corrosion, at several radiator plugs, and have needed to vent air/gas more frequently than I would expect. Also, I have noticed explosive "pumping over in the loft like a fountain" but that's been just after refilling (which I've done slowly) and I've assumed it was simply due to air getting trapped then released in the refilling procedure.

My current "servicing" of the system includes replacing a couple of radiators, replacing suspect valves and plugs, flushing and using X400 and X100.

I have a Potterton Nettaheat 10-16 MkII F, which has not been serviced for a few years, but I plan to have a replacement installed next summer. Six years ago I was told it was in "remarkably good condition", though I'm suspicious about what looks to me like corrosion at the top of a vent pipe projecting up from the back of the boiler.

Any further comments would be very much appreciated.

 

[mickyg]

As suggested, there is probably a problem thats causing this build up of sludge in such a short space of time. This could be a number of things, but if you are serious about getting a new boiler in the near future then your best bet is to carry on with the plan, and when someone comes to put your new boiler in, one would hope they would correct any problems you may have, and your actions will at least give the installer a head start in the flushing.
As for your boiler, I would strongly suggest getting it checked over. The netaheats have a problem, that if there is a small leak at the back of the boiler it causes the back panel to corrode, this compromises the continuity of the sealed casing which in this case is under positive pressure. This is bad news if it happens, so its worth getting it checked over purely for this reason.