Which manifold do I need for splitting out wall radiators?

thewiseowl12

Grateful for any advice.

I have 5 radiators upstairs in my house and I want them to be individually linked back to a heating manifold (as opposed to the existing ring circuit being proposed by a plumber which would replace existing gunbarrel tubing and presumably be handier for him). I want this both for future maintenance and from an efficiency perspective, as I understand this to be a better approach.

There will be TRV's on the radiators themselves, so can anyone suggest what manifold should be used - to be honest the plumber has been rather unhelpful and its proving impossible to source another so I'd prefer to tell him what I want exactly.

Is this the appropriate one or is it overkill?

https://www.suntask.ie/5_Port_Brass_Manifold_With_Pressure_gauge_and_auto_air_vent.html

Many thanks

Lenar3556

Manifolds are usually the way to go. You can eliminate or substantially reduce inaccessible joints /t’s and the system will be easier to properly balance.

The ones you linked are for underfloor heating systems, for standard radiators the below are usually best suited. You can screw any combination of them together to provide the required outlets. There are also wall mount brackets available for them.

https://mybuildingsupplies.ie/shop/plumbing-heating/pipe-fittings/pipe-fittings-brass/compression-brass-manifolds/?attribute_pa_size=3-4-x-1-2&attribute_pa_type-2=3-port&gclid=Cj0KCQiAsdKbBhDHARIsANJ6-jdBdEbTngS_ZvjSt5Qp-x02ntLSHhaFLsGGMPaQnqH5jiF8WUYnHiUaAj1kEALw_wcB

10-10-20

https://www.boards.ie/discussion/2058272064/which-manifold-do-i-need-for-splitting-out-wall-radiators

As a retro-fit? Is that not completely bonkers? You'd have to route two pipes off each rad back to the manifold, tearing up floors and drilling excessive holes in each joist etc, right?

thewiseowl12

https://www.boards.ie/discussion/comment/119884015#Comment_119884015

Thanks very much for that, greatly appreciate it! Last quick one - thats a 3/4" to 1/2" manifold - my understanding is that radiator pipes are normally 5/8" or 16mm? So its a 3/4" to 5/8" manifold I should be specifying?

Thanks

thewiseowl12

https://www.boards.ie/discussion/comment/119884794#Comment_119884794

Very fair comment - I'm pulling down ceilings to insulate between floors so its not really a concern. All pipe holes in joists will be adjacent or on structural walls to minimise impact.

The Continental Op

Nearly all Irish plumbing is in 1/2" and 3/4". Those aren't the outside diameters they are the internal diameters perhaps you are measuring external, it can get confusing. Although thats not strictly true as half inch qualpex is slightly less than 1/2" internally but the same size externally as copper 1/2inch pipe.

5/8ths is the external diameter of 1/2" copper.

heffsarmy

https://www.thetapshop.ie/irish-copper-pipe-vs-metric-copper-pipe/

thewiseowl12

https://www.boards.ie/discussion/comment/119885208#Comment_119885208

Thanks so much!

Doolittle51

I used something similar to the one linked in the OP. Flow and return to each rad in qualpex, so no joints under the floor. I installed actuators on the manifold and a thermostat in each room. Works really well.

The only tricky part was connecting qualpex to the manifold. The manifold connections are 3/4" BSP thread, so I had to use a 3/4" FI to 1/2" Compression coupler. Not really a big issue, but it would have been nicer if there was a way to connect qualpex directly to the manifold with a 3/4" eurocone connector. They don't seem to exist for 1/2" pipe.

thewiseowl12

https://www.boards.ie/discussion/comment/119885341#Comment_119885341

https://mybuildingsupplies.ie/shop/plumbing-heating/pipe-fittings/pipe-fittings-brass/compression-brass-manifolds/?attribute_pa_size=3-4-x-1-2&attribute_pa_type-2=3-port&gclid=Cj0KCQiAsdKbBhDHARIsANJ6-jdBdEbTngS_ZvjSt5Qp-x02ntLSHhaFLsGGMPaQnqH5jiF8WUYnHiUaAj1kEALw_wcB

That would sort that wouldn't it? I've been advised alu-pex is fairly bulletproof so will be going with that if possible instead of qualpex

The Continental Op

https://www.boards.ie/discussion/comment/119885455#Comment_119885455

Should be no problems with those. The will connect directly to copper and 1/2" pex type pipe. Don't forget the inserts with the pex.

Doolittle51

Does Alu-Pex come in 1/2"? If so, basic brass manifolds are fine as you're not planning to use actuators at the manifold. TRVs wont offer great control though. A room stat and actuator for each rad would be much better. Unless you're planning to use wireless stats and TRVs?

cruizer101

I did this recently, manifold in hotpress with 5 rads upstairs and 5 downstairs, rather than the circuits around outside of house, also meant downstairs instead of old pipes coming out of the ground with multiples bends to line up with radiator they just come out of wall direct in to the rads so much neater and cleaner floor.

A lot of the manifolds are for underfloor heating and are designed for having actuators. I went with simpler ones like this https://www.heatmerchants.ie/x-iso-valve-3-way-heat-merchants-pro-manifold-u42100 they have a valve but more for just turning on and off, was handy for filling system after replumbing as could just open one at a time. Got 4x 3 port and 4x 2 port to make 4x 5port, upstairs and downstairs flow and return, then pipes with no joints to the rads (there are some joints in mine as for some I finished with bit of chrome pipe but no joints are required). TRV's on all the rads then to control room temps, looking at getting some smart ones now shortly.

thewiseowl12

https://www.boards.ie/discussion/comment/119886628#Comment_119886628

Thanks @cruizer101, really appreciate it - did you use alupex out to the radiators? I'm wondering if something like this would work? https://www.screwfix.ie/p/jg-speedfit-15bpex-100c-push-fit-pe-x-barrier-pipe-15mm-x-100m-white/69170

cruizer101

I just used standard qualpex and compression fittings, I did look into some of the fancier ones and Hep20 a bit but I can't see there being any issues with the standard qualpex, that said I'm not a plumber so don't have a lot of experience

thewiseowl12

https://www.boards.ie/discussion/comment/119911765#Comment_119911765

Cheers for that @cruizer101 - last question(!) - how much did the manifolds set you back if you don't mind me asking?

Thanks

cruizer101

The 4 x 2 way and 4 x 3 way, which I needed to make up 4 x 5 way cost 128, they are 3/4" BSP in and 1/2" compression out.

The ones I got are slightly different to the ones on the website I've attached pic, you'll want end caps for them also as open at both ends, can't remember what they cost, few quid. I used pipe thread seal on the threads to join them, you could just use ptfe but I kinda prefer the thread seal over ptfe as always bit unsure how much ptfe to use to get seal I think the thread seal is bit more amateur friendly but best do your own research and decide.