blocked pipe mystery?

[vass]

Hi all,

Apologies if this is a little long winded but im completely lost with the central heating issue i am having and i am hoping someone has experienced a similar issue and can offer advice!

I moved into my house almost 2 years ago. When i moved in the house got a powerflush done, an inhibitor added and a magniclean fitted to prevent future problems. The system was perfect following that. This winter the 3 radiators furthest from the boiler were not heating properly. (livingroom, porch and downstair toilet). The water was black and after removing one rad it was filled with sludge.

I called the engineer that carried out the flush and he has determined that there is no flow to these rads which seems to be due to a blockage. He spent some time trying to clear the block using a pressurised hand pump which failed to clear it. Then we removed floor boards up stair to get into the pipework where they tee off. This section was flowing ok. The pipes are 10mm plastic and apparently problematic?

Next he inserted a rod into the pipe leading downstair. It came up against some resistance that was eventually cleared but only as far as the length of the rod inserted.

after numerous efforts to to clear the blockage using the pump and cleaning agents etc there was no joy and it seems that the thin plastic piped have blockages in the straights and it is clumped up lumps of black matter (rust?). It is not wet and sludge so much but more crumbly and relatively dry.

The engineer has been down a few times and after each attempt it seems that other rads that were hot are cooler and vice versa. They all seem to change regularly. Some are hotter, some cooler and they change each time work is carried out.

The powerflush machine was ran through the system again and after a full day of trying everything there is no real change.

My plumber seems to think that the plastic 10mm pipes are the issue and if cleared may block again. After a complete clear 2 years ago and crystal clear water her has never seen a system get so clogged up again, with various rads changing temp all the time and not being able to clear a blockage. There is still no flow down to the porch and toilet. The livingroom is piping now but not sure how long for.

My plumber, who has tried everything in his arsenal after 20+ years experience has said he has done all he can short of replacing all the pipes, This would mean great expense and major upheaval in lifting all flooring upstair. I would love to avoid that if possible but apparently the current pipe work will mean this will continue even if the block is cleared on this occasion.

Can anyone offer any expertise or thoughts on this issue?

Any help greatly appreciated!!

Thanks!

 

[Gas2Air]

Re-pipe. Sorry.

 

[bazdaman]

As above if hes powerflushed it again and tried cutting sections out its repipe time, did he say anything about the plastic pipes letting oxygen in or anything? May be wring type of plastic, is it a sealed system or open vented?

 

[ScottishGasMan]

Very little point powerflushing 10mm plastic, you wont get anywhere near enough flow up through the radiators to remove sludge lying in the bottom of them. Also a powerflush machine doesnt work on a blockage so you could hook it up all week like that, wont make a bit of difference.

Honestly its a repipe, you could replace current blocked pipes (which would no doubt leave fittings in places they shouldnt be) and then individually remove all the rads and mains flush outside. But youd still need to remove the current blockages

 

[vass]

Thanks for the replies. I think the only reason the power flush was hooked back up was a last attempt to try something so all avenues were exhausted before a re-pipe was the only option left. He did say that it is pointless when there is a blockage. Worth a go i guess.

He did mention oxygen getting in the pipes. Cheap rubbish apparently.

As it happens my neighbour on one side said they had a British Gas powerflush 2 years ago and now sludge affecting one rad. My neighbours on the other side had British Gas cover and when some of their rads went cold they were told they needed a full re-pipe but they wouldnt touch it and gave them a full refund of what they had paid so far.

Obviously all houses constructed with the same pipes. built about 15 years ago.

Anyway i appreciate the replies and i knew answer really but hey, worth gaining some more insight into!

Thanks!

 

[Gas2Air]

Do you know who the builder was? Sounds like non barrier to me. Your plumber has done really well trying to get it going. Most would've given up.

 

[kittedup]

Any money it's non barrier pipe

Repute is the only answer.

Ted

 

[vass]

110% effort from the plumber for sure! Just as frustrated as me it wasnt resolved!

So does non barrier mean it allows oxygen into the system? Why ask who the builder was, should they not have fitted this type of pipe? Should i attempt to contact them?

Thanks again!

 

[holty]

lets just say. i tried a hand hydraulic pump on a run off 10mm non barrier pipe. gave up after it went past 10bar. repipe needed. no matter what.

 

[Schvink]

Definitely a pat on the back for your plumber. None barrier is not ideal to use for central heating more for DHW or DCW services but you can get away with it some of the time if the system is properly treated and maintained with inhibitor etc. Personally don't think that the builder will entertain it to be fair but dont ask dont get after all.

 

[doitall]

Perhaps the plumber should try suction instead of compacting a blockage.

End of the day it needs to come out so irrelevant to a point.