Blocked pipes - central heating system cleaner

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Avocet

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System is oil-fired (Worcester Heatslave). Everything was fitted in 1995 when the house was built. The pipes feeding the radiators are 10mm, a mixture of copper and plastic. Some of the radiators barely get warm. (Rooms furthest from the boiler).

For one room, I was able to pull up the carpet and floor boards and replace the plastic pipe run from its manifold to the affected radiator. The pipe was full of black, crystalline "sludge". It was quite hard "sludge" though. It made cracking noises when I tried bending the pipe. I put corrosion inhibitor into the system after doing that job.

Sadly, the pipe run to the other radiator is longer, and runs under a cork tiled floor which has been glued to plywood, which in turn, has been nailed to the T&G chipboard floor, so pulling it up would be a massive undertaking!

Are there any tips and tricks for this sort of problem, please? I was wondering about giving the system a heavy dose of Fernox or Sentinel cleaner? I've also seen adverts for a device called a "magnaclean" but presumably, that wouldn't do anything once the pipe is blocked? (It's not completely blocked - not yet, at least)! Does powerflushing work?
 
Powerflushing is often sold when not required as a cash cow, but in your case well worth a try before the pipes block completely.
 
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1. If the pipe is completely blocked, there will be no flow through it and no chemical will have any action on it.
2. If there is some flow, a cleaner (X400, X800) will work. If very little flow could take a long time. I'd use one you can leave in for a week or two.
3. An Adey Magnaclean (or other maker's equivalent) will pull magnetic sludge out of the water. You can isolate the Magnaclean at its built in valves, remove magnet and rinse off the sludge, replace and turn the water back on. Do it hourly for a short time, then once a week gradually reducing to once a quarter / half year when it doesn't attract much between cleanings. Best fitted on the return as close to the boiler as possible. Use in conjunction with cleaner. When cleaner finished and system drained, re-fill and add inhibitor.
 
Avocet said:
The pipe was full of black, crystalline "sludge". It was quite hard "sludge" though. It made cracking noises when I tried bending the pipe
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I cannot see any cleaner ever removing that ..god knows what the boiler is like...
 
durhamplumber said:
I cannot see any cleaner ever removing that ..god knows what the boiler is like...
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Boiler seems OK. Don't use those two rooms much, and being so far from the boiler, I think that's just where debris seems to collect. I guess anything that is in those pipes isn't in the boiler!
 
You cannot powerflush 10 mm pipes as the cross sectional area is not large enough to give a good flow through to dislodge sludge. Bob
 
BoilerBob said:
You cannot powerflush 10 mm pipes as the cross sectional area is not large enough to give a good flow through to dislodge sludge. Bob
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OK thanks, but can I use the FX2 power flushing cleaner like an ordinary cleaner and just leave it in there for a few weeks?
 
Avocet said:
OK thanks, but can I use the FX2 power flushing cleaner like an ordinary cleaner and just leave it in there for a few weeks?
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No ... That cleaner is like X800, it's very strong and aggressive and is only designed to be used at the time of cleaning. It is not designed to be left in long term as it will eat the system from the inside out if you do.

You need a cleaner that is designed to be used over time - X400/F5 etc - can be left in for a > week
 
Hi again everyone. I'm resurrecting this thread as I've finally got round to putting the cleaner into the system and it's been in there for about three weeks now. I'm going to drain the system down, but in order to get as much of the gunk out as possible, am I best doing that when it is hot or cold? i.e. should I run the system to get it hot, and get everything circulating round and then drain immediately, or should I leave it to cool before draining, or doesn't it make any difference either way?

Also, does anyone have any recommendations for inhibitor to add, or are they all pretty much the same? I already have about 1/3 of a can of Sentinel X100 from last time, so if that's as good as anything, I'll just get some more of the same.
 
Drain hot (unless for some reason the cleaner says otherwise) you want to shift as much as possible, lots of flushing with clean water before finally putting in the cleaner.
Hot it should run better like draining the oil on a car. X100 is as good as any.(y)
 
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