Super_Paulie

cant thank you guys enough for all the info, its keeping me on the straight and narrow (hopefully). If you have a moment can you cast your eye on this drawing @Nickfromwales to let me know im on the right lines with all of this? mainly because i dont know anyone how has used a buffer tank or who has UFH so getting answers from pals is non-existent. also: a) using the buffer as 2-port, am i right in thinking that you need the return connection top and bottom rather than say both coming in at the bottom or does it not matter? b) how do i fill the thing, just via the filling loop on the boiler? Multiple pints are owed due to all the info from you lads.

yeah ive been looking at your drawing and ordering up the gear i need for the weekend. 1.1/4 bushes down to 1" then compression elbows. I assume i need a bottle vent or similar for the top of this thing and a drain at the bottom?

this thing is heavier than id imagined!

sorry for the spam guys, guilty as charged. In fact... i can tee this into the UFH return before that returns back to the primary return surely? The bypass rad wont return circulate into the rad circuit because the UFH doesnt come back in until after the height of the last rad?

this drawing might be more accurate. I guess the solution is a separate tee just for the bypass rad as i assume the bypass return needs to be the highest back to the boiler.

would i be right in thinking that a bypass radiator return tee'd in below the height of the last rad would make the radiator circuit warm by reverse circulation? i guess the only way out would be a separate return like the UFH return, higher than the last rad?

I know what you mean but space is an absolute premium sadly. I could do it, but it would be a multitude of bends to get things back where I need them. Hopefully maintenance will be few and far between and draining down the top leg of this shouldn't be too much hassle... We'll see!

That's what I was hoping. The bathroom is only small, 3x3 so a small radiator/towel rail with no trv was my thoughts and bin off the bypass. That'll work right? Seems a nice day for plumbing.

Ok, well despite what I said above, here is my hopefully final attempt. It dawned on me that I need access to the flow upstream of the valves so I can have a towel rail hot whenever the boiler is fired no matter if it was radiators or UFH and to have it also act as a bypass? So I've came up with this. Hopefully this is all present and correct?

ok, I think this is how i will do it, would someone be able to sanity check it for me please, thanks in advance! Am i ok to run full-bore butterfly valves under these 2-ports, dont have much room (im aware the 2-ports are upside down in the photo, was just to keep the cable out of the way) Id assume a wise man would also have another couple of butterfly isolation valves on the return just before and after the buffer tank, seeing as its the highest point in the system?

Done and ordered. Onwards and upwards!

Scrub that, the room I have available is ideal for that Cordivari... That's the one I think I'm going to go for, although it seems sold out everywhere for some reason other than a private sale on eBay.

this tank seems more readily available, any experience with this one? its floor mounted but they have a wall mounted one available as well, just need to check my available space.

yeah the downside is that i have literally no where to put a tank in the way the house is being set up, its relatively small and minimalist. I'll check tonight but i should be able to get a tank in the loft right next to the boiler, in fact may be able to get a larger floor standing one, the loft is fully boarded out and has nothing but the missus's shoes in it... That ebay link and their store @Nickfromwales are sold out of the 50l sadly, but i have emailed them. There is a "new" one on ebay for 200 notes which i could possibly go for.

right, i think im with you guys. Sorry, hard to get your head around this the first time around and your input is much appreciated. So are you saying simply attaching the buffer tank within the return, blanking off the other ports, and it just sits there "dumb" with no control is the best way to go? And my wiring centre just operates as normal, calling for heat from the boiler whenever a zone asks for it. So i guess kinda like the attached (simplified):

Been looking at the 4 port tanks, especially the one Nick suggested there, the volano termico. As well as sounding like a hell of a drink it looks pretty nice as well and I have the room for it. Looking at it and working out how to connect it, does it simply sit within the flow and returns (before the zone valves) or is it specifically on the flow and return for the UFH? also it seems to have no electrics at all, so my wiring center would still connect to the boiler "call for heat" as before? This sounds ideal as it's getting more complicated than I initially had hoped.

thats interesting. As my downstairs is the only place to have the UFH, it is basically 2 rooms. A 4mx4m front room and a much larger wrap around that is all open plan, maybe triple that size. I could treat the entire downstairs as a single zone, it likely wouldnt be an issue to do so and it would likely eliminate the short cycle? it would just mean i dont get that control of the smaller room, but will that even be an issue i wonder... Would i be right in thinking that the buffer goes within the flow and return just after the boiler and the wiring centre (Heatmiser UH8) will connect to the buffer instead of the boiler call for heat?

ive been looking into it as im new to the UFH gamer and hadnt even considered the short cycle until recently, in fact didnt even know it was a thing.... im struggling for space to fit a tank, the house is pretty minimalist living so the only place would be in the loft and even that is tight... The one in the picture actually looks pretty tidy though, havent seen one that slim during my research, any idea what model it is?

Nick, thanks a bunch. Sorry for calling you out, but you seem to be the guru on here and its to your credit, cant thank you enough for the time. I plan on installing the 2-ports in the void/cupboard within the old chimney breast, the existing pipes run up to the boiler on the side of the breast. Would you agree to the (simplified for clarity) diagram attached? 2 full-bore butterflies (levers?) just below the ports for the possible exchanges of the valves? This forum and people like yourself have really spurred me on in what is my first big renovation. (UFH and inevitable short-cycling still to come...)

hi guys, is there any reason why i cant do the following: Both 2 port valves side by side on the first floor. It would streamline my plumbing to do so as my manifold area is getting quite bogged down with things, so looking at any positive/negatives for that. I can have a valve down at the manifold if i really to, so i guess its either or. My preference is both up there to keep them together. Any reason i shouldn't do this, @Nickfromwales, you are the fountain of knowledge on here so i take what you say as gospel, but im open to any advice from all you fine gentlemen/women/others. Size is not to scale, obviously i need to run the cables to the wiring center and UFH is for the entire ground floor also.

Yeah designed by a few companies but most came back the same. No one mentioned short cycling but I guess they probably wouldn't... I'll get my lines in and then get back to the research, cheers John.

Sorry, loop. 4 (or 5, I forget) loops split between 3 thermostats. It's all been designed, I don't know the ins and outs at the moment as I don't have the documents handy. Any thoughts on the reverse circulation, that's where I'm at today. Cheers

4 zones, around 90m each is currently designed so hopefully that is ok for the combi. Just the reverse circulation I was hoping someone could clarify for me. Cheers for the response John 👍

Gentlemen. Got a few days to hammer out some plumbing, so I'm going to lay the flow and returns for my ufh. For context, combi is in the loft, ufh (manifold, pump, wiring center etc) is ground floor. 2 port valves can live in the void/cupboard within the defunct chimney breast just below the boiler on the first floor. So I've designed a dedicated flow and return, but my question is at what point can I join the return to the primary heating return? Does it have to be higher than the last radiator so as to avoid return circulation? If so, how high is high enough, is it physically above the last radiator or can it come from the same/last tee. Cheers gents. Pictures a bit of a bodge, best I can do on my phone!

its maybe 3m from the joint to the boiler, boiler just above loft floor level so the pipe run up the side of the chimney breast in the copper. So a 22-15-15 would surfice, be pretty easy to be fair as i already have all my copper in until the new joint so i can just plug into it. Alteratively i could break into the copper higher up and convert from 22 to 15 there, but not sure it would make much of a difference?