DIY power flushing or let the pro's do it

[Gray0689]

If its Hep2o non barrier it could be blocked solid !

Why??
5 year old hep would be barrier pipe

 

[Toddyplumb]

You can get barrier or Non barrier ( black writing on non barrier and its cheaper ) Non barrier lets oxygen molecule in and the inside of rads corrodes like mad !!!!!! Blocks 10mm pipe solid , the water looks like oil !
Flushed one last Friday , luckily 15mm pipe so brought it back to life used 3 litres of inhibitor on completion but no guarantee !

 

[Gray0689]

You can get barrier or Non barrier ( black writing on non barrier and its cheaper ) Non barrier lets oxygen molecule in and the inside of rads corrodes like mad !!!!!! Blocks 10mm pipe solid , the water looks like oil !
Flushed one last Friday , luckily 15mm pipe so brought it back to life used 3 litres of inhibitor on completion but no guarantee !

Never seen it before

 

[tamz]

Never seen it before

It is sold to be used on plumbing only but the cheapskates use it to save a couple of quid. As there is no oxygen barrier it can sludge up pretty badly.

To the OP
As said before it is highly unlikely it will need a powerflush.
Have you actually seen the colour of the system water or are you just going on what you have been told. Some of the big gas players use it as an excuse for everything when most times it is not needed.

Potterton do fixed fee repairs if you don't know/trust anyone local you can use

Link
[DLMURL="http://www.potterton.co.uk/117.htm"]Potterton[/DLMURL]

 

[denyason]

the evidence is black water, cold spots on radiators and my combi boiler cuts out- heating and water don't work together, so either water or heating. when its heating, it will cut off after an hour- something to do with pressure or the sludge possibly.
not new system- it came with the house, 5 yr old new build. but recently added a large radiator from an extention.
the initial problem was fixing a valve- to controll 2 independent thermostats; one for living, one for sleeping. only one thermostat communicated with the boiler so only downstairs had heat and upstairs nothing.

 

[Gray0689]

the evidence is black water, cold spots on radiators and my combi boiler cuts out- heating and water don't work together, so either water or heating. when its heating, it will cut off after an hour- something to do with pressure or the sludge possibly.
not new system- it came with the house, 5 yr old new build. but recently added a large radiator from an extention.
the initial problem was fixing a valve- to controll 2 independent thermostats; one for living, one for sleeping. only one thermostat communicated with the boiler so only downstairs had heat and upstairs nothing.

Yes sounds like it's sludge but after 5 years is ridiculous
Ifit is this non barrier pipe you got a long term problem

 

[tamz]

Sounds like you would be better off long term repiping the lot

 

[justlead1]

Hi. Although this is something i know little about. Flushing systems seems to have become an industry, surely system materials and design account for this. Has any one considered changing the medium used to fill closed circuit heating systems? That is not water based.

 

[Gray0689]

Sounds like you would be better off long term repiping the lot

I agree with tamz

 

[Bernie2]

The thing is the black sludge is called magnetite, which in simple terms is steel rusting. But to get it to rust you usually need air getting into the system. Its a sealed system "So where is the air coming from?"

Sure enough water itself contains some air, but possibly not enough to rust the system that quick. So where else?

Sure flux and wire wool left in the system when first filled can cause problems, after all flux is intended to clean metal, which basically means it eats into its surface, which in turn can advance the rust process or perhaps help what little air there may be in the system rust it quicker.

You would be talking about a lot of rust to cause blockages though. So where would lots of air get in?

Well the main culprit seems to be the plastic pipe. If you get a microscope and look at the walls of a plastic pipe you will probably see its full of tiny holes which let air molecules in, but not the bigger water molecules out.

That is not what you want on a central heating system.

So they paste a barrier substance over the pipe to fill the holes up, a sort of plastic Polyfilla if you like or a bit like fibreglass resin pasted over fibreglass matting. So the pasted pipe is known as barrier pipe.

Problem is you can't really do much about it, if none barrier pipe has been used as Tamz says, except replace it or face the prospect of radiators wearing out very quickly after all its probably the steel they are made of that is the magnetite, in other words it could be liquid radiators your pouring down the drain.

As to the flushing, its relatively easy you have just got to make sure you flush out everywhere. That description on the other website is good. But I would find out why its rusting so quick first.