Second opinion on microbore please

23 Mar 2011
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United Kingdom
Please excuse a question for a first post but I’m after some advice.

I have a microbore central heating system which does not seem to be working very well. My heating is insured by a major formerly publicly owned company and they came and had a look today and says that it has sludge (which is probably likely) and because it is microbore it cannot be power flushed. The recommended solution is I think (perhaps in my ignorance) utter over kill. They have suggested that the whole central heating system should be repiped to 22mm with 15mm drops to the rads and that all the rads should be replaced. Additionally because my boiler is old although it still functions they have recommended it is replaced. Total cost approx ~£7000. of which ~£5k is for the repiping and new rads.

Now I can’t help feeling that he has said repiping is necessary because he doesn’t like microbore. I don’t either and wouldn’t have fitted it but it is there already, under my floorboards and newly laid carpert and isn’t (I don’t think) leaking. So I would have thought leave it alone.

To remove the sludge, as the system is microbe, I would have thought the rads should be removed and flushed in the garden. As it happens I think they would benefit from renewal as they’re pretty ugly and have clearly been there a good few years.

The boiler I am aware it is old and when it packs up is may need replacement but surely I should wait until it packs up before replacing it?

So I have two questions, firstly do the professional recommendations appear reasonable?
Secondly would draining the central heating system, replacing all the rads be as good a solution to the problem of sludge?
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Microbore can be flushed,but not that easy to get the flow through it to flush,i would stick x800 in it for 2 weeks.
Then powerflush system with kamco fx/2
After i would stick x100 in.
what boiler do you have in now , how many rads , bedrooms bathroome etc
stick some sludge remover in it for a while before you start thinking of spending that sort of cash , seems to me they priced up aa mansion :)
The boiler is called ideal, I think it is about 15 years old.

I'll still have to drain the system with sludge remover though right?
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if its a combi you could isolate an upstairs rad drain it and add it into that , if its a gravity fed system just drain enough to empty the f+e tank pour it into that and refill it again
though obviously you'll have to drain the system to remove it :D
and as lightning said use x800
It all depends on what the problem really is, the size of microbore, if its single ended rad valves etc.

All in all a lot of additional information would be needed to decide whats best.

Certainly replacing with 22/15 mm pipework would not be a bad idea but the cost of that should be about £300-£900.

X800 only needs to be in the system for about four hours and a day is more than necessary but best to drain then next day.

If you must choose BG then you may have a feeling of security but the reality is that you really are paying through the nose for anything that they do.

A reasonable independent will be both better and cheaper!



Independent and cheaper!
The guy has given you good advice 22 and 15 is far better for system to work you say your rads are old and shabby he has agreed. Boiler is 15 years old and working ok, is he that wrong to suggest doing all the work at the same time instead of say maybe have the upheaval again in a couple of years.

The price that is BG for you it can be done far cheaper elsewhere but does that make his advice wrong.

If the system has twin entry valves and is sludged then it cannot be properly flushed or power flushed without taking the rads off.

Agile .£300 to re-pipe a system ? on a standard 2 bundle of 15mm one of 22mm system you could not even buy the materials for that
your heating system not that big, but the price seams abit on the high side. If its worked before then there's no reason it cant work again, If you want another price just let me know. :LOL:
In Coventry they advertise a new boiler and five rads for £1499 !

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