Blocked pipe: Full or partial repiping?

[set]

Dear all,

I have a severe blockage issue which prevents 2 radiators from working and would like to know how far I should go with the repiping and if it is useful to replace the radiators as well, in your opinion.

System
The system comprises: 8 radiators, one 7 year old Saunier Duval ThemaClassic boiler (patched up last year with a new expansion vessel), and a 20 year old piping system (10mm non-barrier plastic).

History
For many years, the system was working well and was not maintained at all. I did not even know what an inhibitor was! I started having heating issues with some of the radiators recently last year.

I eventually managed to find a competent heating engineer, who manually flushed each of the radiators, replaced all the valves, which solved the issue for most of the radiators but 2 (one of the ground floor, one on the first floor).

According to this heating engineers, this was the worst magnetite sludge case he had ever seen . Trying to flush (not power flush) through the two blocked pipes did not prove successful.

My options

Based on what I read on this forum, there is no circulation so the use of sludge remover chemicals would not be very useful (and could damage the joints). Power flushing on a heavily blocked 10mm plastic pipe is not recommended either.
The only option left seems to repipe the system. On the one hand I would like a long term option, but on the other hand I not want to do unnecessary work, after all the system was working fine for 20 years!!

My question!

In my case, what would you do:
- Partial repiping by bypassing the current blocked sections (and avoid any floor tile removal)?
- Full repiping (with copper in surface and plastic underfloor)?
- Would it be useful to replace the radiators?
- Would it be useful to replace the boiler?

Could the best option be to do: full repiping + keep current boiler (still a few years to live) + keep current radiators (have had valve replaced and have been manually flushed) + add magnet filter + inhibitor once a year?

All comments welcome! Many thanks.
[/b]

 

[dcawkwell]

Connect air compressor at radiator end and fire as much force as it needs to clear at each pipe. Then flush through with the mains.

Blockage could be at the manifold rather than the pipes to the radiator.

My guess is you could actually flush it through with the mains cold
anyway.

Refill system with a good doses of inhibitor.

Sorted.

 

[set]

Connect air compressor at radiator end and fire as much force as it needs to clear at each pipe. Then flush through with the mains.

Blockage could be at the manifold rather than the pipes to the radiator.

My guess is you could actually flush it through with the mains cold
anyway.

Refill system with a good doses of inhibitor.

Sorted.

Thanks. The heating engineer actually tried flushing with the mains cold but without success. Maybe compressed air could work, I had not thought about this option. There is the risk of splitting the plastic pipe if the blockage is as hardcore as I suspect but it might be worth a try...if this does not work, what options in my post would you guys go for? Cheers

 

[JohnD]

do you know where the blockage is?

do you know if it is Barrier Pipe? If not, the age and colour may give a clue. There may be a name or other reference on the side.

edit
oops, you said it is non-barrier pipe.
It all needs to be replaced.

 

[gas112]

What about cutting pipes and trying to clear blockage with the flexi rods used to feed electric cables ,providing no elbows or really tight bends it may work

 

[andytw]

Is it possible the pipe was bent with quite a tight radius and put under load and it has now folded at the bend and formed a pinch in the pipe rather than a blockage. I know you have been chasing sludge so, yes, that may well be the problem.
Just providing another option.

andytw

 

[set]

do you know where the blockage is?

do you know if it is Barrier Pipe? If not, the age and colour may give a clue. There may be a name or other reference on the side.

edit
oops, you said it is non-barrier pipe.
It all needs to be replaced.

So, you reckon that repiping all the system with barrier plastic + copper rather than just bypassing the blocked session with a new pipe (for half the price) might be the best solution for long term? Would you also replace the radiators?

Cheers

PS: I will try to see if the air pressure and manual "spoke" fidling are feasiable but I suspect the sludge might be along most of the pipe...