Nickfromwales

Apologies, but only seeing this now. I'll have a look when i get 5 mins, but at first glance it seems a little pointless going for such a small accumulator. That will have <125L of useful volume and is dependant on the incoming cold mains value. Have you done a reading for static pressure and dynamic flow rate yet? To decide on an accumulator volume these need to be known, and your max cold mains dependency understood.

Hi @daiking The 15mm feeds will suffice, you'll just need to put a manual bypass ( standard £5 gate valve ) across flow and return at the manifold, immediately prior to the pipes being connected to it. It'll make almost no difference whatsoever to the running of it, like near zero, and would only really impact the heating up when you want to warm it from cold ( and then TBH you'd not really suffer as 15mm flow and return will still keep a 2600 x 700mm K2 double radiator blasting ) so tell your plumber to have a chill pill and just connect to the 15mm ones you already have. The only time the boiler will 'suffer' ( short cycle excessively ) is when the UFH is used on its own, so I'd try to never have a system configured where that would be the rule, or the exception TBH. When the UFH is up to temp it will require less than the boilers minimum output even at max modulation ( you have a Baxi Duotec IIRC? ) therefore will be a design load that is outside of it's 'happy place'. Running the bathroom towel rads simultaneously at the bare minimum will help the boiler out no end, so at least one of those should stay on manual ( bypass ) radiator valves, but the other 2 (?) certainly should have TRV's fitted. Leave the one in your ensuite on bypass valves and change the others to TRV's so visitors / kiddies are less likely to come into contact with them Plumbers ( on their mothers side ) do this in bathrooms ( leave out TRV's ) as a knee-jerk action, and are bell-ends for doing so. Get those done asap for comfort and safety. The blending valve on the UFH manifold will allow you ( as in you personally ) to adjust the flow temp of the UFH loops to whatever you want, so once plumbed in and commissioned you can tweak this daily. You can get two set points marked with Tippex and change the temp a little 'seasonally' for selecting between the shoulder months and deepest winter for eg, same way folk with boilers turn the flow temp up a bit when the weather becomes a bit sharp. You would do it at the manifold and not the boiler so as to not affect the flow ( surface ) temp of those emitters, again promoting comfort / safety. Connecting this lot up is a doddle, so don't let anyone start tearing pages out of the Problematic Plumbers Bible, simply do as above, connect up the flow and return to the manifold, and get the slab warmed. Remember the 50p per day is only due when you need to heat the slab, so no banks are going to be broken here, and I reckon you'll only need to provide a bit of background heat from the slab to make a huge difference in the house. UFH via a slab is a bloody good way of getting 'comfort' heat into a space, so try it low first and go from there. As far as controls are concerned, run with what you've got and just put a simple £1 1g1w light switch as an on/off switch so you can remove / introduce the UFH as required. Start off cheap and cheerful, and add complexity later if you find it's necessary "Proceed"

The fact that it's coming along is good enough for me !!

A simple capacitor may suffice, but my knowledge is mostly electrical not electronic I’m afraid.

I’d be inclined to say to put a relay in between the switch and the ‘controller’ tbh, as this is the exact same switch that @PeterW and I fitted in @newhome‘s install ( which = “ tried and tested “ ). The relay will not change state with ‘ ghost voltage ‘ but it appears the controller clearly is responding to this sub manis voltage signal so IMO I think that would sort it. @readiescards, Take the live trigger ( output ) wire from the flow switch and have it power the coil in a normal relay ( solid state may not be a good idea ) and have the relay convey the common ( the live into the flow switch ) to the pump controller unit. That should give a definitive on or off signal to the unit and resolve the issue. In @newhome‘s it went; switch > relay > pump and worked well, just yours has an electronic component downstream which clearly doesn’t like ghost voltage.

Coming along nicely

MBC don’t bother, just whack the pipe in and away to go. There’s too much going on on a new build to risk fitting delicate things like manifolds ( flow gauges are very easy to damage ) so I only ever do that now if there’s a pipe been damaged & repaired and it needs proving. Tbh you can just do that with a temp rig anyhoo, so as long as there’s no excessive foot traffic / narrowing then I would say don’t worry. Thats re Pex-Al-Pex with the aluminium liner. It’s tougher than Charles Bronson and Jean-Claude Van Damme’s love child. 👌

Motorised machine with guides that stretch the pipe would be my choice, probably best to hire one. Get everything laid in as far as you can to shorten the window for hire.

Explanation please? Not heard of that phrase before tbh.

I’ve just had 47m of 25.0mm2 3-core dropped off on site and they put it onto a wooden drum for delivery. It was easily put upright and rolled downhill to the rear of the build by myself without any hint of breaking into a sweat. 100m with a hot tub should be fine at 16.0mm2, and at most you’ll need a second pair of hands to roll it down your site. Not anywhere near the issue we had moving your Sunamps lol. You'll have no probs at all, as long as it doesn’t gather speed and Foxtrot Oscar down the valley

Another factual thread that we can all safely rely on then “Taxi for.......”

How about buying a pre-formed concrete tray ( Link ) and set in situ prior to the pour ? Then just let them polish to this and ask the polishers to blend it in as best as possible? I’d say go for a bigger area if no shower enclosure is to be used. 1500x1500mm. Getting closure to match may be controlled by asking what’s the sand comes from for the tray manufacture to forecast if there will be big differences between the two. Sounds a tall order unless you put a break at the door and address the room al-a- @Onoff‘s solution.

….and @PeterW Praise the lord !!!!!!!!! 121 photos in there 😤 Thanks for that, didn't even know that folder existed .

Not forgetting the PCM34 has been out of circulation for what seems forever . Other low temp models will surface soon enough but I’ve no useful info on that yet I’m afraid. Rumour has it that improved, and now ‘on board’, controls are in production so I’ll update ASAP on that as I get some training ( hopefully ). I just got trained up on the fitting of a trio of SA units fed only from a split high temp ASHP for load-shifting off E10. I’ll post some pics when I get copies ( as my daughter was deleting them off her iPad at home as I was taking them after I had linked it to my Apple ID to set it up and had not logged back out 😭😭😭 ). Lost loads before I realised where they were going 💩 Need to see if there’s a way of recovering lost pics off iCloud. Gutted.

In the attic where the 15’s are bunched.