Cold water manifold, how big is toooo big

[SuperJohnG]

On 29/10/2020 at 07:37, Nickfromwales said:

If the OP has 16 x cold feeds ( assuming 3 x WC’s / 2 x cold mains appliances ) that’s 11 outlets requiring cold supplies ( so also assuming 11 hot supplies ) then the cold supply would need to get to at least the first two bathrooms in a minimum poor size of 22mm. Same for the hot, but the hot more like starting off in 28mm, then picking up the first bathroom, and then 22mm from there forward, and then reducing to 15mm as seen fit. Really if a bathroom is the last item then you can’t drop to 15mm until you’ve picked up the shower & bath. 
So, a minimum of 26 x T connections if you don’t adopt a radial manifold setup and fingers crossed after you’ve tested initially and boarded up. 
Another benefit is that for a new / self builder, you can just bring on items as work progresses, so no need to keep draining down / connecting / re-pressurising each time you add a new item. 
And, the party piece is hot return and flow rates. With a large single bore series setup you’ll be waiting for a very long time to get hot water out of basin sinks in particular as they are low flow / high frequency use and by the time hot had got there you’d have got fed up waiting. Pressure and flow rates are as uniform as you can get too, so question has to be.....why wouldn’t you do it? 
Not having isolations on the end of every run / at each outlet is a no-brainer, as most modern bathrooms won’t have somewhere for such valves to be easily / practically accessed, particularly for baths and showers etc. 

Regular ( series ) 0
Manifold ( radial ) 1 ( well 4 actually ). 

God damn.....again the forum  strikes.and gives me a reason to make something better. 

 

I now see the added value.....maybe. 

Edited October 31, 2020 by SuperJohnG

[SuperJohnG]

On 29/10/2020 at 07:37, Nickfromwales said:

And, the party piece is hot return

 Are you talking about adding a loop through the manifold and extra pump? 

 

If I do a manifold then it would be adjacent to the UVC in the plant room. Is there any value there? 

[Nickfromwales]

7 hours ago, SuperJohnG said:

 Are you talking about adding a loop through the manifold and extra pump? 

If I do a manifold then it would be adjacent to the UVC in the plant room. Is there any value there? 

Hot manifold adjacent to the water heater is best practice, and implementation of an HRC ( hot return circuit ) is always gauged on the dwelling. It depends on how far away your basin and sink taps are from the manifold tbh. You could shift the hpt manifold to a strategic centralised location and just have the ( HRC ) running between the UVC and the manifold and then leave as is.. 

Two current jobs for eg's;

1. HRC to hot manifold at the hot water device, kitchen sink as last point of draw off on the manifold to promote flow across the whole manifold ( pre-heat ), HRC pump only pulling back from the kitchen sink therefore the whole hot manifold is warmed routinely hugely reducing waiting times at the other reasonably close outlets. Timer to be fitted for the HRC pump so that operation is in line with activity / occupancy..
2. HRC to hot manifold at the hot water device, HRC pump pulling back from the 2 upstairs bathrooms ( wash hand basins only ), manifold 'warmed' / 'pre-heated' as above, micro-PIR's to be fitted under each of the 2 wall-hung vanity units to trigger the HRC pump. Same PIR's to be used to also bring on ( automatically ) the night-time 'pee lights' under the vanity. Manual lighting circuit will be set to bring pee & other low-level lights on constantly for chilling in the bath ( so no overhead spots need to be on, and no disco lights from the PIR ). Timer to isolate pee lights during daylight hours if necessary.

All depends on the layout of the house, so if you add distances to the basins / sinks from the UVC I can recommend something for you. 

[SuperJohnG]

4 hours ago, Nickfromwales said:

All depends on the layout of the house, so if you add distances to the basins / sinks from the UVC I can recommend something for you. 

Thanks @Nickfromwales I will add some once i calculate. Where donyoubgetbthose Hepworth manifolds you mentioned? Google seems to eluding me! 

[Russell griffiths]

Just now, SuperJohnG said:

Thanks @Nickfromwales I will add some once i calculate. Where donyoubgetbthose Hepworth manifolds you mentioned? Google seems to eluding me! 

I’ve looked on line all week, best price is the plumbers merchants at £42 for a 4 port, you can find them cheaper but not come with no fittings, so the time you add 4 fittings your back to £42. 

[JOE187]

https://www.jtmplumbing.co.uk/search/manifold#sort9

JTM offer a good variety keenly priced!

[Pocster]

4 minutes ago, JOE187 said:

https://www.jtmplumbing.co.uk/search/manifold#sort9

JTM offer a good variety keenly priced!

I also recommend them !

[Nickfromwales]

44 minutes ago, Russell griffiths said:

I’ve looked on line all week, best price is the plumbers merchants at £42 for a 4 port, you can find them cheaper but not come with no fittings, so the time you add 4 fittings your back to £42. 

What fittings? 

[Nickfromwales]

25 minutes ago, JOE187 said:

https://www.jtmplumbing.co.uk/search/manifold#sort9

JTM offer a good variety keenly priced!

https://www.jtmplumbing.co.uk/pipe-fittings-c433/hep2o-brass-manifolds-c661/hep2o-four-port-valved-manifold-15-tm-tf-fp-p21691
 

Remember you can’t mix JG Speedfit manifolds with Hepworth pipe. Has to be like for like for manufacturers warranty to remain intact. 

[Pocster]

2 minutes ago, Nickfromwales said:

https://www.jtmplumbing.co.uk/pipe-fittings-c433/hep2o-brass-manifolds-c661/hep2o-four-port-valved-manifold-15-tm-tf-fp-p21691
 

Remember you can’t mix JG Speedfit manifolds with Hepworth pipe. Has to be like for like for manufacturers warranty to remain intact. 

I used these . They are excellent quality !

[Russell griffiths]

21 minutes ago, Nickfromwales said:

What fittings? 

The cheaper ones I found take a Euro cone fitting, so cheaper manifold but have to buy 4 euro cones per manifold. 

 

Those jtm ones are cheaper and I think they are made by reliance valves who know there stuff. 

[Russell griffiths]

21 minutes ago, Nickfromwales said:

https://www.jtmplumbing.co.uk/pipe-fittings-c433/hep2o-brass-manifolds-c661/hep2o-four-port-valved-manifold-15-tm-tf-fp-p21691
 

Remember you can’t mix JG Speedfit manifolds with Hepworth pipe. Has to be like for like for manufacturers warranty to remain intact. 

Why would you need a warranty, what bit for??

or are you talking about if it caused a flood. 

[dpmiller]

but you could use either with copper...

[Nickfromwales]

6 hours ago, Russell griffiths said:

Why would you need a warranty, what bit for??

or are you talking about if it caused a flood. 

If the pipe failed anywhere they’d look to point the finger of blame anywhere. 
Being sure the Hepworth insets fully seat and seal into an alien manifold is another consideration. 
I won’t be mixing and matching for anybody if I am going to be liable for a catastrophic failure. Water causes a LOT of damage, and that’s if you’re home to stop it. If not, it’s humping out until you discover it. 
Save a couple of hundred quid elsewhere.......?

[trialuser]

On 31/10/2020 at 08:07, Nickfromwales said:

Hot manifold adjacent to the water heater is best practice, and implementation of an HRC ( hot return circuit ) is always gauged on the dwelling. It depends on how far away your basin and sink taps are from the manifold tbh. You could shift the hpt manifold to a strategic centralised location and just have the ( HRC ) running between the UVC and the manifold and then leave as is.. 

Two current jobs for eg's;

1. HRC to hot manifold at the hot water device, kitchen sink as last point of draw off on the manifold to promote flow across the whole manifold ( pre-heat ), HRC pump only pulling back from the kitchen sink therefore the whole hot manifold is warmed routinely hugely reducing waiting times at the other reasonably close outlets. Timer to be fitted for the HRC pump so that operation is in line with activity / occupancy..
2. HRC to hot manifold at the hot water device, HRC pump pulling back from the 2 upstairs bathrooms ( wash hand basins only ), manifold 'warmed' / 'pre-heated' as above, micro-PIR's to be fitted under each of the 2 wall-hung vanity units to trigger the HRC pump. Same PIR's to be used to also bring on ( automatically ) the night-time 'pee lights' under the vanity. Manual lighting circuit will be set to bring pee & other low-level lights on constantly for chilling in the bath ( so no overhead spots need to be on, and no disco lights from the PIR ). Timer to isolate pee lights during daylight hours if necessary.

All depends on the layout of the house, so if you add distances to the basins / sinks from the UVC I can recommend something for you. 

@Nickfromwales, or anyone. As I understand it, one of the benefits of the distribution manifold is the absence of joints on the pipe journey, so this implies plastic pipe.

Can you suggest a plastic pipe that is suitable for a HRC that doesn't need fancy tools to join. I'm struggling to find anything. Many thanks

[Russell griffiths]

6 hours ago, trialuser said:

@Nickfromwales, or anyone. As I understand it, one of the benefits of the distribution manifold is the absence of joints on the pipe journey, so this implies plastic pipe.

Can you suggest a plastic pipe that is suitable for a HRC that doesn't need fancy tools to join. I'm struggling to find anything. Many thanks

They all require fancy tools, I may be about to buy a set that I would sell on afterwards, what makes have you looked at. 

[SuperJohnG]

14 minutes ago, Russell griffiths said:

They all require fancy tools, I may be about to buy a set that I would sell on afterwards, what makes have you looked at. 

What fancy tools are we talking here?  Standard type plastic pipe like speedfit or hep20 just require a pair of snips to make.lofe easier. You can buy cheap ones at 10 quid or say rothenberger for 50 quid. But not much more than that I am aware of? 

[PeterW]

Hep2O is suitable for a HRC, the bronze pump is the only non standard item. In terms of connections, everything in Hep2O is push fit and as @SuperJohnG says you just need a decent set of cutters. I’m on my second pair of these in 10 years. 
 

Only place you then need copper is to make tails for the pump and into the UVC, all the rest can be in Hep2O push fit. 

 

 

[Russell griffiths]

I think @trialuser is talking

about a press fit system that you need the clamping tool, best part of a grand. 

[MikeGrahamT21]

If you want MLCP without the expense of one of those tools, try these: https://pswtradesuppliers.co.uk/

 

I used it for my manifold system for the radiators, and it worked a treat, same kind of system with 16mm pipe, aluminium core, and eurocones, but this has a compression nut instead of needing the tool for press fit.

[trialuser]

Thanks everyone. I had been looking at uponor pipe, the shrink fit which needs a special expander tool. I didn't realise hep pipe was ok for constantly circulating hot water, that makes things much easier. @MikeGrahamT21 what are you linking to, I cant tell from the page, cheers.

[MikeGrahamT21]

49 minutes ago, trialuser said:

Thanks everyone. I had been looking at uponor pipe, the shrink fit which needs a special expander tool. I didn't realise hep pipe was ok for constantly circulating hot water, that makes things much easier. @MikeGrahamT21 what are you linking to, I cant tell from the page, cheers.

 

Its a plumbing supplies company. PSW Trade Suppliers

[Nickfromwales]

Hepworth for HRC needs to be temperature capped so a TMV is required in every instance. I’ve been using the same TMV that goes on the SA units as they’re decent reliable units. I set those to 50oC nominal and happy days. 
The question of how much of an arse your BCO is, whether or not they make you drop the bath to 46oC as “god intended” ( some BCO’s think they’re ‘up there’ for sure, and some are just massive bell-ends ). ??. Best to check before assuming that 50oC everywhere is acceptable. 

Edited November 4, 2020 by Nickfromwales

[trialuser]

Following a bit more research, I'm going to use copper. We definately have a mice issue. I assume that apart from a central point of isolation, there isn't't really a huge benefit to the manifold system.

[ProDave]

On 29/10/2020 at 13:28, pocster said:

Now I’m sure everyone told me 15mm min !! ?

My dad was a plumber.  When he re plumbed my first house there was a long run to the bathroom done in 22mm for the bath.  I argued with him to fit a 10mm pipe from the hot tank to the basin tap for quicker delivery of hot water.  He wouldn't, he said "the water won;t get there any quicker"

 

It was shortly after that I decided to do all my own plumbing......