Plumbing Planning

[MortarThePoint]

I thought I'd start a thread of considerations to do with the plumbing. Below are some pictures that show the proposed layout. I'm presuming that I'll use 15mm for all pipes except those shown as 10mm and probably the stopcock to Water Cyclinder will be 22mm (inc manifold)

 

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[JohnMo]

Take outside tap off first and include isolation and check valve so you cannot contaminate the rest of the system.

 

Have you considered a manifold for cold and hot water, this allows each stream to be isolated.  We found this great when we moved in as main parts of the plumbing was complete but ensuites not complete.

[Iceverge]

We had a mare with ours. I ended up redoing all the plumbing myself in Hep. It's an excellent system. 

 

We had a 13m run to the kitchen tap so in the end I ran a 10mm pipe to that too. About 5-6l/min flow rate. Not as much as the 8l/min for the cold tap but perfectly useable. It might be a consideration if your distance is large.

 

A manifold radial system works a treat. 10mm for all hot basins straight from as near to the cylinder as possible. It works a treat and the difference is really noticeable compared to the ones I left the 16mm pipe from the plumber in place. Hot water in 5secs instead of 25. 

 

Pipe is cheaper than fixings so I don't think there'd be much of a price difference. You get the added benefit of having no fixings hidden anywhere in case of a leak. 

 

[HughF]

Manifold everything..... I'd press it all personally in MLCP but then I've got a press gun with U and M jaws, you might not want to go this far.

[MortarThePoint]

1 hour ago, JohnMo said:

Have you considered a manifold for cold and hot water, this allows each stream to be isolated. 

 

I'd like that. I haven't seen a Hep2O manifold that can do that yet, but maybe it's less widely carried that 5he simple non-isolating manifolds.

[JohnMo]

These are what I used.

 

https://www.outsourcedenergy.co.uk/product-category/manifolds/plumbing-manifolds/

 

[MortarThePoint]

1 hour ago, HughF said:

Manifold everything..... I'd press it all personally in MLCP but then I've got a press gun with U and M jaws, you might not want to go this far.

Interesting I hadn't seen that system before.

[MortarThePoint]

Need to add appliances: washing machine, dishwasher and option for fridge

[Thorfun]

I loved the idea of a manifold system even one where each room can be isolated from the plant room. but when our plumber came to price up the job and I mentioned it he said it'd cost a lot more and we'd need 24 pipes from the plant room instead of 3. we will have 4 bathrooms, 2 x WC, kitchen and utility room so with each having a cold, hot and HRC it just seemed excessive amount of pipework for a convenience that I don't know when/if we'd ever need (isolating a room that is).

[HughF]

5 minutes ago, Thorfun said:

I loved the idea of a manifold system even one where each room can be isolated from the plant room. but when our plumber came to price up the job and I mentioned it he said it'd cost a lot more and we'd need 24 pipes from the plant room instead of 3. we will have 4 bathrooms, 2 x WC, kitchen and utility room so with each having a cold, hot and HRC it just seemed excessive amount of pipework for a convenience that I don't know when/if we'd ever need (isolating a room that is).

Yes, but you don’t need any fittings? And mlcp on a coil is cheap as chips these days….

[JohnMo]

Our manifold isn't in the plant room, as it would have meant lots of long runs of pipes.  So it's right in the middle of where it needs to be.

 

Hot water

Kitchen goes off to the left in the plant room and isn't on the manifold, manifold pipe goes right and it located in the utility cupboard. One supply to each room and branches of within the room.

 

Cold water

Manifold same place as hot, all room piping is under the floor insulation within the concrete (ducted). A supply branches off to plant room.

 

I have secondary circulation to the furthest away room only, this heat the manifold up by default.

 

[JohnMo]

[Thorfun]

27 minutes ago, JohnMo said:

Our manifold isn't in the plant room, as it would have meant lots of long runs of pipes.  So it's right in the middle of where it needs to be.

 

Hot water

Kitchen goes off to the left in the plant room and isn't on the manifold, manifold pipe goes right and it located in the utility cupboard. One supply to each room and branches of within the room.

 

Cold water

Manifold same place as hot, all room piping is under the floor insulation within the concrete (ducted). A supply branches off to plant room.

 

I have secondary circulation to the furthest away room only, this heat the manifold up by default.

 

our plant room is in the basement but is pretty much central to the house so it wouldn't be a huge increase in pipe length to put it there rather than in the cupboard that is on the ground floor directly above the plant room.

 

I might ask our plumber to cost up the manifold and extra pipe and see how much extra it would be.

[MortarThePoint]

12 hours ago, MortarThePoint said:

I'd like that. I haven't seen a Hep2O manifold that can do that yet, but maybe it's less widely carried that the simple non-isolating manifolds.

 

A bit of pocking around and I have found some (up to 4 way):

 

https://www.jtmplumbing.co.uk/pipe-fittings-c433/hep2o-pipe-fittings-underfloor-heating-c999/hep2o-brass-manifolds-c661/hep2o-four-port-valved-manifold-15-tm-tf-fp-p21691/s27296

[Iceverge]

Initially the plumbers used MCLP crimp fittings for us.

 

A couple of thoughts.

 

The system looks like it would be capable of very high pressure as the system mimics hydraulic fittings. I suspect it is almost impossible to get a leak if the joint is crimped properly. Scraped pipes seem to be less of an issue than with push fittings. (I didn't have any issues however)

 

All connections need a special tool, although it could be rented. Its not very DIY friendly if you want to make a small alteration later in that respect. If you decide to change a fitting your only option is to cut it off and throw it away. There's no second chances unlike de-mountable push fit fittings.

 

I found the inner bore of the crimp fittings is quite restrictive compared to Hep2O or copper although in practice the flexitails for most taps seem to be smaller than both anyway. 

 

The MCLP pipe is semi rigid which has pros and cons, it can make a tidier setup in the plant room as it retains its shape when bent but is more difficult to cable through joists etc like Hep. The 10mm Hep is almost like running electrical cable.

 

In practice the need to isolate outlets at the manifold individually won't happen that often in a domestic setup. If it does need to happen for a period with Hep2O manifold in a radial system all you need to do is demount that pipe and put in a stopper. 15 secs work. 

 

Here in Ireland we still use the old imperial fitting. (bangs head against wall emoji)

The MCLP is continental 12mm 16mm 20mm 26mm etc.The fittings we use are British metric, 15mm 22mm etc so a typical connection done by the plumbers was

 

MCLP 26mm pipe 

26mm to 3/4 Irish crimp fitting with brass tail 

3/4 to 22mm nut and olive

22mm British isolation valve 

22mm to 3/4 nut and olive

3/4 brass tailed crimp fitting to MCLP

26mm MCLP pipe.

 

Mental compared with a push on 22mm Hep2O pipe valve on 22mm pipe I replaced it with.

 

Not such an issue in the UK but worth considering how you will combine MCLP and British fittings.

 

Another point ( I know people will tell me to use a water softener) is that with all plastic and Stainless Steel Hep2O won't degrade like copper/brass in an acidic borehole water situation. 

 

 

 

 

 

 

 

[HughF]

12 hours ago, Iceverge said:

Initially the plumbers used MCLP crimp fittings for us.

 

A couple of thoughts.

 

The system looks like it would be capable of very high pressure as the system mimics hydraulic fittings. I suspect it is almost impossible to get a leak if the joint is crimped properly. Scraped pipes seem to be less of an issue than with push fittings. (I didn't have any issues however)

 

All connections need a special tool, although it could be rented. Its not very DIY friendly if you want to make a small alteration later in that respect. If you decide to change a fitting your only option is to cut it off and throw it away. There's no second chances unlike de-mountable push fit fittings.

 

I found the inner bore of the crimp fittings is quite restrictive compared to Hep2O or copper although in practice the flexitails for most taps seem to be smaller than both anyway. 

 

The MCLP pipe is semi rigid which has pros and cons, it can make a tidier setup in the plant room as it retains its shape when bent but is more difficult to cable through joists etc like Hep. The 10mm Hep is almost like running electrical cable.

 

In practice the need to isolate outlets at the manifold individually won't happen that often in a domestic setup. If it does need to happen for a period with Hep2O manifold in a radial system all you need to do is demount that pipe and put in a stopper. 15 secs work. 

 

Here in Ireland we still use the old imperial fitting. (bangs head against wall emoji)

The MCLP is continental 12mm 16mm 20mm 26mm etc.The fittings we use are British metric, 15mm 22mm etc so a typical connection done by the plumbers was

 

MCLP 26mm pipe 

26mm to 3/4 Irish crimp fitting with brass tail 

3/4 to 22mm nut and olive

22mm British isolation valve 

22mm to 3/4 nut and olive

3/4 brass tailed crimp fitting to MCLP

26mm MCLP pipe.

 

Mental compared with a push on 22mm Hep2O pipe valve on 22mm pipe I replaced it with.

 

Not such an issue in the UK but worth considering how you will combine MCLP and British fittings.

 

Another point ( I know people will tell me to use a water softener) is that with all plastic and Stainless Steel Hep2O won't degrade like copper/brass in an acidic borehole water situation. 

 

 

 

 

 

 

 

I picked up a ‘for parts or not working’ press hun off eBay about 2 years ago, an early geberit cordless one that doesn’t have any electronics in it so doesn’t stop working after 30k presses. It needed some hydraulic oil and a battery. I’d never go back to soldering or push fit. I love the fact that mlcp will form a bend, and it’s always available cheap as chips off Facebook 😂 I recently got 100m of wras approved 16mm for £5 😏

[crispy_wafer]

I had this post stashed away in my scrapbook (ideas and great things others have done) so may help with the hep2o manifold ideas

 

 

[MortarThePoint]

I want to clip my 15mm and 10mm pipes to the underside of the concrete HCF flooring. I'll be using standard pipe insulation that has a 13mm wall. The standard clips, example below, look to leave less than 13mm between the pipe and whatever the clip is mounted on. Can anyone recommend on that is better for this as I don't want to have to kink my pipe for each clip or have the insulation pushing the pipe out of the clip.

 

  

[MortarThePoint]

Talon do spacers, but it looks like a bit of a bodge:

https://www.talon.co.uk/products/pipe-clips-and-accessories/pipe-clip-accessories/standard-spacer

[MortarThePoint]

I like the idea of having completely separate loo feeds (10mm?) Which go all the way back to the manifold. Makes swapping to harvested water easy. Additional pipe and clips probably adds £50. Water is about £1/m3 and 20 flushes per day would work out as around 10p/day, so £37/yr. May make sense. Any harvesting method wouldn't have zero annual cost though.

Edited May 31, 2022 by MortarThePoint

[Thorfun]

1 hour ago, MortarThePoint said:

I like the idea of having completely separate loo feeds (10mm?) Which go all the way back to the manifold. Makes swapping to harvested water easy. Additional pipe and clips probably adds £50. Water is about £1/m3 and 20 flushes per day would work out as around 10p/day, so £37/yr. May make sense. Any harvesting method wouldn't have zero annual cost though.

we're having RWH with a header tank in the loft for our toilets so the toilets will have separate feeds from that tank. this means that when I'm having a shower and someone flushes the loo it doesn't affect the water or temperature! 

[Nickfromwales]

23 hours ago, Thorfun said:

we're having RWH with a header tank in the loft for our toilets so the toilets will have separate feeds from that tank. this means that when I'm having a shower and someone flushes the loo it doesn't affect the water or temperature! 

You could just keep the several thousands of pounds in your pocket and fit a cold mains accumulator.

RHW....... In the summer you're still using potable drinking water, in the winter it's already raining every few days.

IMHO, a waste of time and money with NO breakeven point, as the pumps fail and cost a lot to replace. You cannot even fit a bypass to supply potable water to those select outlets as the water is classed as category 5 ergo you cannot make a physical link between the two systems.

 

Use the money to buy more PV

[Thorfun]

2 hours ago, Nickfromwales said:

You could just keep the several thousands of pounds in your pocket and fit a cold mains accumulator.

RHW....... In the summer you're still using potable drinking water, in the winter it's already raining every few days.

IMHO, a waste of time and money with NO breakeven point, as the pumps fail and cost a lot to replace. You cannot even fit a bypass to supply potable water to those select outlets as the water is classed as category 5 ergo you cannot make a physical link between the two systems.

 

Use the money to buy more PV

ahh...we've had this discussion many times before Nick. we're not doing it for any financial reasons or payback period or anything like that. we're doing it so we're less reliant on mains water. Also we have a constant stream of water running under ground around the basement to our sump which, even in dry weather, means that the RWH tank will be filled so, for us, the 'no rain in the summer' argument doesn't stack up.

 

Also our header tank is fillable from mains water in case of drought as the system uses a 'brain' to manage it all. it will also flush out the tank if no use is seen after a period of time, e.g. on holiday, to replace the rainwater with mains water so the rainwater isn't sat in the tank for a long period of time. it's all rather cool.

 

so, remember, it's not always all about repayment periods for everyone.

 

Also, we can't buy more PV.....roof is full. 😂

[Nickfromwales]

2 hours ago, Thorfun said:

Also, we can't buy more PV.....roof is full. 😂

Ah, lol, can't blame a man for trying   I do forget who I 've said what to, as there is a huge amount of traffic on BH these days.

Solar pergola?