Sludge microbore system

[tomsim]

On a system if rads are cold at the bottom hot at the top. This is likely sludge? Worst on downstairs rads. Is an open vented system cast iron hex. Is power flushing the best option. Or would taking the rads. Outside to flush individually be better? Is microbore so concerned of clogging pipework with settled sludge at bottom of the rad. Thanks

 

[Madrab]

It's not advised to powerflush microbore due to the bore size. If there are manifolds there is a danger of flushing more of the crap into the system and it becoming even more blocked.
Usually there isn't sufficient flow through the system due to the bore size to get an effective flow rate to clear out the system properly.

You are better to run cleaner in and let it run for a week or 2, system condition dependent, drain the system, remove the rads and flush them individually and then do a flush through the system out through the valves with mains water.

With an open vent system, if it is really dirty you may also want to check the feed and vent where it joins the system pipework for build up (use a magnet), that section may also need cut out and replaced.

 

[tomsim]

There is no manifold but 8mm pipework to the rads. Is the feed and vent tee a usual point of blockage?

 

[Madrab]

There is no manifold but 8mm pipework to the rads. Is the feed and vent tee a usual point of blockage?

Is it just 22mm with multiple reducers to 8mm, that would be a little unusual.

Yes, it can be a choke point, depends on the condition of the system and if it's bad, then how long it's been like that.

 

[tomsim]

It's 22mm main runs tee'd off in 15mm then reduces to 8mm for the drops.

 

[Madrab]

Never the best I wish they had never invented 8mm copper for CH systems they really are the worst. Even 10mm's crap after a while.

All I would do is cleaner in, run for a week or 2, drain, rads off and flush them, fill and flush through the system to the valves ensuring that you get a good clean flow at all the valves. Then rebuild system and fill with loads of inhibitor.

 

[tomsim]

As power flush could clog 8mm?
Is a magnite good for diagnosing slugde in a system?

 

[Madrab]

Yes a powerflush can move larger pieces of debris that might be in the larger pipework that is ok in the larger pipework but when it gets to the 8mm it then blocks it, especially at bends and such like. Any experienced CH engineer would normally refuse to powerflush microbore.

Sludge is, in the main, magnetite. Basically it is a type of Iron oxide that doesn't go red.

 

[tomsim]

Thanks I can imagine the sludge in the bottom of the rad. Maybe pretty thick. Open vented so have to drain abit out of the system to get sludge remover/cleaner in to the header tank?

 

[tomsim]

What is the best cleaner to put in? X800?

 

[Ihavenojob]

Do you have twin entry valves (2 pipes into 1 valve) or a valve at each end of the rad? Twin entry ones have a distribution tube, and they can fall off

 

[tomsim]

There not twin entry no. Just 8mm to each side worse rads are downstairs on drops

 

[tomsim]

Yes a powerflush can move larger pieces of debris that might be in the larger pipework that is ok in the larger pipework but when it gets to the 8mm it then blocks it, especially at bends and such like. Any experienced CH engineer would normally refuse to powerflush microbore.

Sludge is, in the main, magnetite. Basically it is a type of Iron oxide that doesn't go red.

So a magnite up against the copper would should sludge if it is magnitides

 

[tomsim]

Is x400 or x800 best?

 

[Madrab]

X400 is best over the longer term. X800 is super aggressive and can't be in for long. X400 can be left in for a week or 2.

If using cleaner make sure it is well flushed clear.