RichJ

Thanks for the photo Nod. But how would you connect the plastic pipe to the lockshield/trvs? I'm assuming it's not into the bottom of the valves like copper pipes coming up from the floor would do.

Did you get your manifolds from PSW? Are you happy with them? Did you go for the brass ones or stainless?

So 22mm plastic as in Hep2o?

Might go with these for converting to copper... https://www.thefloorheatingwarehouse.co.uk/product/compression-fit-to-copper-adaptors/

I've gone with a 6 port manifold from Wunda with their eurocones for 16mm Pex-Al-Pex/Pert-Al-Pert for about £160. Not cheap but it's apparently good kit. I need to source some ball valves for the inlets from somewhere yet. https://www.wundatrade.co.uk/shop/home/quick-shop/wundatherm-quick-shop/manifolds-quickshop/6-port-premium-manifold-2/ For some reason a lot of online sellers now seem to prefer Pert-Al-Pert over Pex-Al-Pex, but am probably going with the Pex-Al-Pex from these guys https://www.thefloorheatingwarehouse.co.uk/ I suspect the missus won't appreciate feeding plastic pipe directly into the rads (visually). I might try it out as a test - running the pipe up through the floor at the centre point of the radiator and looping it round behind the radiator. Alternatively I'll go with something like this under the floor https://www.elementshop.co.uk/16mm-x-15mm-coupling. As you can probably tell, I've not nailed down much yet. But I've decided where the manifolds can be located that will work well.

Hi again Mike I've ordered a 6 port manifold from Wunda.. should be installing it in my cellar/basement to cover the downstairs and basement radiators as a test before tackling the upstairs rads. Did you get any problems when the boiler pump was set to a lower speed? Oh and did you run 22mm copper as the flow/return to the manifolds (then 16mm plastic to the radiators)? I'm wondering whether to use 25mm plastic for the flow/return in my case, but I have no idea what 25mm plastic is like to work with.

Wow. Shouldn't I be paying you for responding in seconds?? So obvious. I owe you one.

Hi Does anyone know if you can get pipe lagging (Climaflex etc) for insulating 16mm Pex-Al-Pex pipes? I'm thinking of running Pex-Al-Pex between manifolds and radiators in my new central heating setup. I've found PSW Trade suppliers have a pre-insulated pipe (https://pswtradesuppliers.co.uk/ufh-pipes/771-1182-multilayer-composite-pre-insulated-pex-al-pex-pipe-16-32mm-for-water-system.html#/14-color-blue/87-size-16mm_x_100m_coil) but the insulation on it is only 7mm whereas I'd prefer something closer to 20mm. Any ideas?

With the Plasson 32mm MDPE stop tap you can go to 28mm copper using a copper conversion set in the outlet.. https://plasson.co.uk/product-category/mechanical/line-7-grey/conversion-and-adaptor-sets-line-7-grey/conversion-set-for-copper-pipe/

<deleted post>

If you're willing/able to swap the 32mm JG stop tap for a Plasson 32mm (compression) stop tap instead, you can use a Plasson 32mm to 25mm reducing set in the outlet of the Plasson stop tap to go straight from 32mm MDPE to 25mm MDPE in one fitting. So you wouldn't need the 32mm to 25mm JG reducer in that case. See https://plasson.co.uk/product-category/mechanical/line-7-grey/valves-line-7-grey/compression-stoptap-valves-line-7-grey/ and https://plasson.co.uk/product-category/mechanical/line-7-grey/conversion-and-adaptor-sets-line-7-grey/reducing-set-conversion-and-adaptor-sets-line-7-grey/ The only thing about the Plasson 32mm MDPE stop tap is it's huge (174mm long). I don't know how that compares to what you already have.

Hi I've been in contact with Wunda re using their 'Premium stainless steel Manifolds' with radiators as opposed to UFH. They've come back with 2 concerns: 1, the flow rates in the radiators might be too low 2, running the manifold at the higher temps required for radiators (50+ degrees) might affect the life of the components Are there concerns valid? I haven't heard anyone of the forums here refer to problems like these...

Hi I've seen a few posts on here where it's been mentioned that if you're using Pex-Al-Pex pipe, you can bring the pipes up from the floor in the centre of radiator... looping the pipe round and down behind the radiator then into the TRV/lockshield. Has anyone got any pics of what this looks like when done? My plan is to convince the missus this is a good option rather than going with copper from the tails to the floor.

Hi I'm trying to work out what I need to implement a DHW manifold setup. I have a query re the hot water aspect. I'm planning to run a 22mm cold mains feed from the main stop tap down to a Viessmann 100 combi, tee'ing off just before the boiler (in 22mm) to a cold DHW loop like shown in the photo (photo obviously lifted from another post on here). The DHW loop will be made up of 22mm copper and Wavin Hep2o manifolds. The hot DHW will come from the 15mm output from the boiler and run in 15mm to a hot DHW loop. In contrast to the cold DHW, the hot DWH loop will be made up of 15mm copper and Help2o manifolds. My question is, if I just feed the hot DHW from the boiler straight into a manifold with no loop in the pipework so the water can only flow into the manifold from one direction, will this prioritise hot water to the ports closest to the inlet? Is this a means of say prioritising the feed to the shower?

Hi Thanks for your replies. Sorry I cut some pretty important detail out from my original post just because it was long enough already. I can see it reads like I was suggesting connecting the boiler up to pex. That's not my intention at all. For DHW I'll be using Wavin/Hep2o barrier pipe and their manifolds. For heating I'll be using UFH manifolds such as the ones from PSW with a mix of copper / pex-al-pex pipe. In all cases the pipework within about 2 metres of the boiler will be copper / end feed.

Hi I'm at the design stage for replumbing my first house. There's loads of cast iron, lead, imperial copper of all different sizes all over the place and the hot water performs so badly, I'm up for starting again with everything except the boiler. The house has a full length dry-ish cellar and also a converted attic so there's 4 floors. I've found places to locate manifolds in a fairly central location on each floor so I'm thinking a manifold system for both the DHW and heating would work well. I have a Viessmann 100 combi boiler is in one corner of the cellar approx 1 metre away from the bottom of a false wall. This false wall (approx 2.75m high) goes up through the kitchen eventually hitting the bottom of the airing cupboard. I'm thinking of taking copper from the boiler to the top of this false wall (as single 3m lengths i.e. no joints hidden) then converting to Hep2o or Pex in the bottom of the airing cupboard. So there will be joints in the bottom of the airing cupboard but nowhere else other than at the manifolds or the rads etc. The reason for this is occasionally we get random animals in the cellar / attic (shrews etc.) so I'll risk plastic in the main part of the house just not the cellar or the attic. I was wondering if anyone could help me with some things I'm not sure on? Sorry they're so basic, I haven't seen anyone else on here asking about these kind of things. 1, I've been looking at the manifolds from PSW trade supplies for the heating. Is there any difference functionally between a plated-brass manifold and a stainless one or is just cosmetic? 2, The inlets on the PSW manifolds seem to be 3/4", can I use Pex-Al-Pex for this or does it need to be 22mm copper? If I can use Pex-Al-Pex what size pipe would I need? I guess it would need to be 25mm maybe? 3, The install instructions on the PSW manifolds say that have to be installed vertically. What would happen if I lay them flat? 4, Most of the pipes PSW sell seem to be Pert-Al-Pert rather than Pex-Al-Pex. I get the feeling that wasn't the case in the past as a lot of the posts on here mentioning PSW refer to Pex-Al-Pex. If I'm going to be using a combi with a flow temp of 50-60 degrees, is there any disadvantage to me using Pert-Al-Pert rather than Pex-Al-Pex? Thanks so much for any help!

Hi I'm a new member, but I've actually been lurking on here for a long time:) I'm hoping to redo my central heating pipework fairly soon and just wondered what the benefits are of using manifolds on a central heating circuit rather than the usual flow/return loops 'teeing' off to each radiator? Also despite looking through lots of threads, I haven't been able to work out whether it matters where I put the flow/return manifolds. Being a new member, I've been slightly unclear on what I'm trying to find out. Sorry If I annoy anyone by revising this post a few times. Thanks