Open Loop Vaillant Arotherm Plus 10KW. Keep it Simple? 

😎👍🏻

It’s just Armaflex taped with class zero tape 👍🏻

We’ve done a similar split upstairs / downstairs cascade with a pair Viessmann vitocals. You will have better low modulation performance and ultimate control in this configuration in my opinion. Not sure you could open loop a true cascade as it would probably need a buffer I would have thought. There is nothing wrong with a buffer, not everyone is interested in chasing the last few percentage of performance. Its a central heating system not formula 1 car

Vaillant is better priced, easier to get hold of, easier to quote for, better manufacturer support, no need for indoor unit so fits in a smaller space and vaillant seem to know Their product better than Viessmann BUT the Viessmann controls on the 150a are superior to the Vaillant.

Not required (it's not shown on the vaillant schematics at least) I don't use 2 ports or over heat stat on gas either if I'm fitting a Viessmann boiler with an ntc sensor on 4 pipe. G3 police haven't arrested me yet... 🚓

@@griffithsheatingBuilding Control would not give you a completion certificate with no 2 Port on the UVC here in Jockoland mate!!!

I’ve just had the 5kW version installed with identical 50L volumiser, my installer (Heat Geek Elite) confirmed it was not just for defrost cycle but also ensuring there was enough volume in the circuit to prevent the ASHP cycling as much as it might without it (due to size of my system aside from the volumiser)

Over 4

No blending. Just letting the heat pump do its thing unrestricted.

@@griffithsheating it makes sense, less expensive mixer station/pumps better savings. Is this your standard going forward then? Do you just run one stat for the whole house?

@@gerardfry4876 there is a wireless Vaillant senso comfort controlling it so you can either run it as a room stat or just off a curve with no room influence. Not sure how the customer will want to run it yet.

And if the pump on the HP can’t supply the index circuit with enough flow, would you fit a buffer then?

@@gerardfry4876 yes if my calculations are wrong I’d have to convert the volumiser to a buffer and add another pump.

I was thinking more of minimum run times when it’s mild out. I have seen Arotherms ice up though even when volume seems to be ok.

Nope, the open loop system becomes the volume you need for Defrost, been installing like this for decades already.

@@kenbone4535 Specially with UFH you have lot of energy mass around in case you need any excess energy for defrost.

Sensocomfort

Let's just say we had a disagreement about the part L building regs 😄 They claimed all heating systems have to be designed to 45 degrees and I called 🐂💩 and 7 months later I'm still waiting for a BUS grant payment. I guess I'm not cool enough to join their club.

@@griffithsheating what did you design to? Sounds out of order to me

@@jacbisgood2221 designed to 55 due to rad space available but that's knowing the home owner is doing a load of additional insulation in the roof space and floor so will end up around 45/50 mark. It actually was finally signed off and grant paid today as it happens 😎

@@markfernandes2467 it’s not a buffer

@@griffithsheating Is there a difference then? What does a vollumiser do then and why did you use one of those?

@@markfernandes2467 yes. A buffer provides a hydraulic break between the heat pump (primary side) and the system (secondary side). So an additional pump is required for circulation in the secondary side. If the flows are poorly balanced between the primary and secondary side you get what’s called distortion where the heat pump may be delivering 45 degrees but the buffer is only supplying 40 degrees so the heat pump has to run at 50 due to achieve 45 degrees in the system. The upside of a buffer is that you can get away with murder on the system design and the heat pump won’t notice but your efficiency will suffer. There is a bit of dogma around buffers amongst the pseudo online big brains. They’ll decry buffers from the rooftops and smugly rip an install apart because it has a buffer. I have Viessmann systems running buffers with scops almost touching 5 after nearly 2 years. A volumiser is essentially just a big tube of water sitting inline just to increase water volume in the system to help with defrost volume or to increase compressor run times when it’s mild out.

Ufh flow rate is set by the manifold flow setters and the rads can be set with either a flow balancer or flow setting rad valves. Or you could use what’s called a stad valve

@@griffithsheating Cheers it is a Grant Aerona with a low loss header only 9 rads the T1-T2 is only about 2-3 nightmare.

@@Allegedly2right bare in mind that your dt will only be at design (5, 7, 10 or whatever) when you are on a design day which is a day below zero degrees outside. Anything more than that the dt will narrow.

Sshhh don’t talk about the gas boiler or Kevin 🤫 we ran out of big clips. I’m not arrogant I’m just better than 99.9% of everyone else. I qualified 6 months ago so have a lot of experience.

Boiler was obviously part of the old system to be ripped out.....🙄........

to the bloke that needs an electric bender because he carnt pull a bend ' also pull youre head out of kevins ass and crack on with youre rad valves and tap washers Dick ' fairplay lads looks like you know what youre doing ' 💪💪