Central heating - Microbore manifolds

[Stripey]

Hi - first timer here. We have a microbore system and have had continuous problems with one radiator not heating up. We had a plumber in to drain the system and he reckons it is probably a blocked manifold(??) . Given that floors upstairs around the pump are all carpeted....how might we locate the manifold(s) to check them out? He also advised the answer if we can't locate them is to get the system pressure cleaned/flushed? But this will cost £400 - is that reasonable?
Help and advice most gratefully rreceived!

 

[chrishutt]

If it's a blockage on the manifold connection all you have to do is force some flow down the pipe in question which will probably clear the blockage, or prove that there isn't any. If you're up to it you could use mains pressure water or compressed air to blast through. Or find yourself a plumber with a bit of imagination.

 

[HarrogateGas]

If he intend on Jet flushing, it wont work with 8mm pipe and your wasting time and money.

 

[Stripey]

Chris - how do we locate the pipe in question - yopu mean at the in end of the radiator in question? How can we connect mains water to it? What would be an appropriate source of compressed air?
We still have the issue of being unable to locate the manifolds without taking up the floor?

 

[chrishutt]

You need a decent plumber or heating engineer to sort it out. I'm araid it's not something that I can be bothered explain in detail via this forum.

 

[bripl]

feeling lazy chris

 

[chrishutt]

Bripl, I just don't want to stay up all night trying to explain the whole procedure. But if you feel up to it, be my guest......

 

[Stripey]

Am trying to avoid having to pull up the floor to locate these manifolds. Would weolcome any useful suggestions re. compressed air, or hooking up the mains to flush the manifolds via radiator pipes.
Thanks

 

[tanguero12]

We have the same problem - one radiator downstairs not working, microbore system. Plumber has searched without success for manifold under some of the the floors upstairs. I have asked others on the estate with same type house but no idea where to look! How can I find the manifold so the plumber can try to deal with the problem?

 

[yerino]

Are you sure its deffo a blocked pipe? Could it just not be air.. and your plumber is taking you for a ride?

Turn off every hot radiator via your thermostatics/lockshields and leave your cold one open on max.

Still cold? Blockage
Gets hot? Sorted!

 

[TonyW2]

The manifold is most likely to be somewhere around the pump area and you may find that your cat has a habit of sitting just above it (ie floor gets a little bit warmer than elsewhere.) Or you may be able to see it via gap or a pipe hole in the uncarpeted area of the cylinder cupboard.

Am assuming you have an open expansion system.
Mains pressure blow out involves opening a drain point whilst a hose is thrust down the c/h supply pipe from expansion tank and "sealed in"--(or connected by another fitting) to pass mains pressure round the radiator system. Vent needs blocking, or bypassing etc --BUT-its a big but- if you have any dodgy joints, you will have a pretty wet house!
//www.diynot.com/forums/viewtopic.php?t=38902

 

[doitall]

Turn rad valves off and disconnect radiator.

open valve and see if water comes out, repeat the other end.

If in either case nothing, connect hose pipe to mains and give it a quick blast.

WARNING.

If it's a sealed system don't over pressurize the boiler or radiators.

 

[tanguero12]

Thanks all for the advice. I will see how we get on. Will push a leaflet through all our neighbours' doors asking if anyone has had a similar problem (all houses were bulit about 11 yrs ago). I will post here with the results.

 

[gasmick2]

Hi i have been to loads of micro bore systems installed in the Leicestershire area that have not had mainfolds fitted, they have 22 mm pipe from the boiler then reduced to 15 mm under the floors then to 8 mm under the floors before it goes to the twin entry valves my own house has micro bore and the manifold is under the stairs cupboard on the surface with isolating valves , and has a mixture of 10mm and 8 mm outlets, i am soon about to update my system to a w/b greenstar but i an keeping my exsisting micro bore sytm as its all solid floors and it all runs ok

mick