Scotland

Expansion is 12 litres, so should be fine? Do you think 90 - 100 litre buffer will be ample.

Yes that would be my fault, I added a ivar blending set into ufh manifold due to posts I was reading from yourself. But upstairs yes it would be good and only realising now I need the extra pumping capacity, but didn't really need to blend as radiators can take the full heat.

Not sure what the expansion size is, I will check tomorrow. Is there not a slight delay though on the actuators opening after the call for heat and the pump turning on?

That never even crossed my mind to do that, Would a manifold bypass then be needed on the other side of the manifold, in case the pump started up and all zones are closed? Back to the buffer, would an expansion tank be required or is the one already fitted on the heating side enough.

Think it's about 1.8 bar when not running, drops to 1.5 bar when running. No pumps on rad circuit yet, but going to add some. The 2 pipes going up the wall go into a tee at the top into a 7 port manifold then it goes to the other side of the house into another 5 port manifold. First manifold gets some movement in the flow meters but the second one doesn't. Currently researching this also as where the manifolds and pipes are would be hard to get a pump in unless I take the pipes to the other side of the manifold, and add a pump there.

@PeterW Peter, the drawings were just for reference as to where the pipes went not on where to break into them. The position of the buffer is the only feasible position to put it as the room is quite small. Keep seeing 2 or 4 pipe setups for buffers so I assume I need the 2 pipe version. Any recommendations as to what buffer to buy, My guess would be something along the lines of 100L ish.

Hello, I'm looking for a bit of advice on adding a Buffer Tank to my ashp setup. The way my heating is set up I have individual control of all rooms in the house via thermostats, downstairs via ufh zones and upstairs radiators via point to point plumbing manifolds. Which in itself probably promotes the use of a Buffer. System specs - Mitsubishi ecodan 12kw Pre plumbed 300l cylinder 95m2 of ufh 249m2 of heated rooms all in. So the question is where is the best location to break into the pipework to install a buffer and looking for recomendations as to Manufacturer, model numbers etc. Pictures are just after installation before someone mentiones insulation etc ? Thank you.

Sw2-1 to on, for mine anyway.

Yes,I can also confirm in1 is what you need to connect into, Works like a treat on mine now.

@ProDave Connecting in all the actuators did the trick, all working as it should now. Thanks. Just the heat pump to sort out now, will have a look at it again at the weekend when I have more time.

Heatmiser neostat v2. Probably have a multimeter lying about somewhere. Bit weird though that the ones with actuators are off but ones without are on, Tomorrow I'll temp fit all the actuators and see what difference that makes. If any ?

When the fused spur to the wiring centre is first switched on it looks like this No stats calling for heat in above picture. When stat is calls for heat the heat light and valve light as well as the zone light comes on, the way it should work. Problem is when the stat is turned off, the heat & valve light are still lit. Like the picture in the last post. Where the problem might lie is have a look at the zones where the actuators are plugged in, they are completely out. The zones without actuators are partially lit but not fully. They look like the power light when calling for heat.

Finally making some progress with this now, (sw2-1 set to off) I switch on ufh wiring centre and heat pump turns off and doesn't turn back on again until I turn the wiring centre off again. So I take it I need to turn sw2 -1 to on. The other problem seems to be the heatmiser uh8 wiring centre, when no stats are calling for heat the valve light and boiler light are still on, any ideas on what the problem could be. But when the main switch is put on from scratch the boiler light and valve light don't turn on until a stat calls, then don't turn off again. Even when no call is sent. Do all the actuators need wired in before it works properly as I have some left off right now.

That could be the answer then, I know I shouldn't have but just changed the switch when the machine was still on. Thanks for the help everyone and I will report back tomorrow when I try it again.

Thanks, I didn't have much time to mess about with it tonight but I changed the cabling to in1 and tried it with the sw2-1 switch in both directions but didn't seem to work, I possibly had to give it more time so I'll try again tomorrow, Could also be how I'm using the heat pump right now, I only get working on the house at weekends atm so just switch the heat pump on say Fri night or sat morning and run it on flow temperature of 25 which is the minimum I can set it too, takes the chill away which is fine right now. Would this setup work with flow temperature or do I have to put it on room temperature or compensation curve modes, Could also be because I have 2 heatmiser uh8's and 1 uh4 connected via wago wiring centre to the cylinder for call for heat. 2 of which are switched off right now as they control radiator circuits. I might try disconnecting this tomorrow and run call for heat wire direct from ufh heatmiser to the cylinder, for troubleshooting purposes.