Manifolds

[Big Neil]

Hello all,

 

I'm interested to know if anyone has used manifolds for distribution of hot and cold water, whether primarily for a reduction in intermediate joints or otherwise. also if you didn't, was there a particular reason why?

[Dudda]

I've used them and would recommend them. It's very easy to isolate a particular outlet if required. One main reason I did was for hot water you can use a smaller diameter pipe to the outlet from the manifold and therefore it doesn't take as long for the water to become hot in addition to wasting less water. eg a 10mm hot water pipe from a manifold to a wash hand basin will have hot water very fast. If this was a traditional with larger diameter pipes and branches and 't' it would take a lot longer. A pumped hot water return system would be faster again but have heat wastage from the circulating hot water.

 

 

[MikeGrahamT21]

Its a very good idea, as you say for circuit isolation, but don't be fooled, it is very expensive! I've just put a manifold in for wall hung radiators, 7 circuits, whole project cost me around £500 (excluding the new rads I needed).

[Alexphd1]

@MikeGrahamT21  a good point you raise but opener is asking about a manifold for domestic hot and cold which only needs a basic manifold with isolating valves (no flow gauges/pumps etc). 

Will be starting to pipe our manifold shortly but my father is not 100% on idea, he thinks I'm nuts even considering 12mm mlcp pipe for feeding basins etc. Hope he's wrong!

[joe90]

I sort of have, by using hep 20 bits, no isolation valves but good for distribution.

Edited November 16, 2018 by joe90

[Gone West]

@Big Neil yes we used manifolds. As others have said easy to isolate individual circuits and no joins in pipes.

 

 

 

[ProDave]

I made my own.

 

 

This is positioned above the ceiling in the utility room and will be accessed via a small "loft hatch"

 

The overriding objective was to enable individual isolation while piping the hot water runs as short as possible without adding extra length to any circuit.  Putting the manifold anywhere else, e.g in a cupboard would have made 1 or more hot pipe runs longer than necessary. 

[Onoff]

25 minutes ago, PeterStarck said:

@Big Neil yes we used manifolds. As others have said easy to isolate individual circuits and no joins in pipes.

 

 

 

 

All that needs is a soft lit glass display case over it to show it off! 

[Jeremy Harris]

I just bought a couple of plain manifolds with 15mm connections (not expensive, IIRC they were around £15 each at the most) and added in-line shut off valves on each leg, to isolate each room with a hot/cold water feed.  Works pretty well, and I doubt it cost any more than plumbing the house any other way.  It also made it easier to ensure that I have no pipe joints hidden in the ceiling or walls, as the run of pipe from the manifold in-line valve to the point where it pokes out of the wall to supply something is a continuous length of pipe, with no joints.

 

 

[Gav_P]

It seems to be a fairly common approach for self builders to use a manifold based installation. I wish I had seen this forum before I started my house... especially when I discovered one of my joints leaking in a ceiling. ??‍♂️

 

I’ll definitely put a manifold distribution in my next house! ... and a nice pretty one too!

Edited November 16, 2018 by Gav_P

[Big Neil]

On 16/11/2018 at 17:03, JSHarris said:

I just bought a couple of plain manifolds with 15mm connections (not expensive, IIRC they were around £15 each at the most) and added in-line shut off valves on each leg, to isolate each room with a hot/cold water feed.  Works pretty well, and I doubt it cost any more than plumbing the house any other way.  It also made it easier to ensure that I have no pipe joints hidden in the ceiling or walls, as the run of pipe from the manifold in-line valve to the point where it pokes out of the wall to supply something is a continuous length of pipe, with no joints.

 

are there pictures on your blog sir?

On 16/11/2018 at 16:29, PeterStarck said:

@Big Neil yes we used manifolds. As others have said easy to isolate individual circuits and no joins in pipes.

 

 

 

 

That is pretty!!! It's not at all what I had in my head, but i like it. I just imagined there would be one big pipe in (the supply from the mains), then one row of blue and another of red (hot and cold obviously) with various pipes going to outlets. Can you clarify for me please what I see here, from maybe top to bottom and left to right?

[Jeremy Harris]

7 minutes ago, Big Neil said:

 

are there pictures on your blog sir?

 

 

This is one taken before I insulated the pipes and when we still had the big thermal store fitted, rather than the Sunamp (hot manifold is at the top, cold at the bottom, and there are no flexi pipes on them any more, they were a temporary bodge to get water on quickly for testing):

 

[Big Neil]

So have you replaced the plastic with copper? If so what was the reason. Was plastic just wrong for your setup?

27 minutes ago, JSHarris said:

 

 

[Pete]

3 minutes ago, Big Neil said:

So have you replaced the plastic with copper? If so what was the reason. Was plastic just wrong for your setup?

 

He means he has removed the flexi pipe feeding the manifold, not removed the plastic pipes.

[Big Neil]

with you Pete - obvious now i look at the picture again.

 

[Jeremy Harris]

Yes, @Pete is right.  I plumbed the whole house in plastic wherever pipes were behind plasterboard or under floors, so that I would run a continuous length of pipe without joins out to every point.  I used copper for all the stuff from the ends of the plastic runs to everywhere else, especially where it might be seen, as plastic tends to look a bit untidy (unless you're @PeterStarck...).

 

The thermal store (green thing) in that photo has gone, and there's a Sunamp sat there now, and the feeds to the ends of the manifolds are 22mm copper.  All the pipes are insulated now, too, you can get a glimpse of them at the right hand side of this photo:

 

 

The DHW mixer valve is fitted directly to the end of the hot manifold now, with the hot water from the Sunamp coming up at the base of it and the cold mix water coming in the top.

[Pete]

3 minutes ago, JSHarris said:

Yes, @Pete is right.  I plumbed the whole house in plastic wherever pipes were behind plasterboard or under floors, so that I would run a continuous length of pipe without joins out to every point.  I used copper for all the stuff from the ends of the plastic runs to everywhere else, especially where it might be seen, as plastic tends to look a bit untidy (unless you're @PeterStarck...).

 

The thermal store (green thing) in that photo has gone, and there's a Sunamp sat there now, and the feeds to the ends of the manifolds are 22mm copper.  All the pipes are insulated now, too, you can get a glimpse of them at the right hand side of this photo:

 

 

The DHW mixer valve is fitted directly to the end of the hot manifold now, with the hot water from the Sunamp coming up at the base of it and the cold mix water coming in the top.

What manifolds did you use Jeremy?

[Jeremy Harris]

1 minute ago, Pete said:

What manifolds did you use Jeremy?

 

I honestly can't remember, other than that they were brass four port ones that came with 15mm pipe fittings.  I thought I bought them from Screwfix, but they don't seem to list them now.  I know they weren't very expensive.

[Pete]

4 minutes ago, JSHarris said:

 

I honestly can't remember, other than that they were brass four port ones that came with 15mm pipe fittings.  I thought I bought them from Screwfix, but they don't seem to list them now.  I know they weren't very expensive.

Jeremy I am so disappointed you have not got it on a spreadsheet somewhere!!. Thanks for the response

[Gone West]

6 hours ago, Big Neil said:

That is pretty!!! It's not at all what I had in my head, but i like it. I just imagined there would be one big pipe in (the supply from the mains), then one row of blue and another of red (hot and cold obviously) with various pipes going to outlets. Can you clarify for me please what I see here, from maybe top to bottom and left to right?

That's essentially what it is, but because of the lack of space I had to split the cold feeds into two manifolds. There is a 25mm main coming up through the floor into a 28mm double check valve, then 22mm stop cock and pressure reducing valve. The pipe bends right, round the corner and tees off to the manifold with white taps which is hard water for drinking and toilet cisterns. The braided pipes are for the water softener which then goes through a pressure reducing valve to the Genvex Combi hot water tank and to the other two cold water manifolds. All manifolds have a ball valve to isolate them.

[Big Neil]

Peter - that is superb - thank you very much. I will try and digest on the bus on the way home

[Bitpipe]

28 minutes ago, PeterStarck said:

That's essentially what it is, but because of the lack of space I had to split the cold feeds into two manifolds. There is a 25mm main coming up through the floor into a 28mm double check valve, then 22mm stop cock and pressure reducing valve. The pipe bends right, round the corner and tees off to the manifold with white taps which is hard water for drinking and toilet cisterns. The braided pipes are for the water softener which then goes through a pressure reducing valve to the Genvex Combi hot water tank and to the other two cold water manifolds. All manifolds have a ball valve to isolate them.

 

Out of curiosity, why would you not use soft water in WC. We have one internal tap that is hard (Nordic Qooker) and everything else is soft.

 

 

 

 

[Gone West]

1 minute ago, Bitpipe said:

 

Out of curiosity, why would you not use soft water in WC. We have one internal tap that is hard (Nordic Qooker) and everything else is soft.

 

It's cold water so there aren't problems with scale and it means we use less salt and regenerating water.

[billt]

48 minutes ago, PeterStarck said:

It's cold water so there aren't problems with scale and it means we use less salt and regenerating water.

 

You can't have hard water then! Ours scales things just as well with cold water.

[Jeremy Harris]

14 hours ago, billt said:

 

You can't have hard water then! Ours scales things just as well with cold water.

 

So did ours at our old house.  Main problem was that newer cisterns do a sort of trickle top up after the flush, to get the water level up to the right level, and this results in a  sheet of slow moving water running down the back face of the pan for ten seconds or so after a flush.  This area always ends up covered in scale, as does the area around the underside of the pan lip.

 

All the toilets in the new house flush on softened water, mainly because it was always my job to sit there spraying Vaikal up and all around the toilet pans to try and get the blasted scale off.  Our water isn't has hard as @PeterStarck's. either, as our total hardness is around 280 ppm IIRC, damned hard, but perhaps a bit lower that that in East Kent.