PeterW

Ok so he’s talking about adding an unvented cylinder to the system which isn’t a bad idea. Mixing UFH and rads you will also need a buffer tank - probably in the region of 100 litres. Have you got attic space where these could go ..? Move the boiler too..?

Would think the blending valve is at fault. Can you take some photos of the setup..?

What is the floor construction method ..? Under the furniture is fine, under the tray or WC pan is a no.

All here

@Fraser Lamont I’ve added all the comments to a new thread for you

First question - does it need to be blockwork ..? You could do this with a timber framed building sat on piers or screw piles, and remove the issue with having to clad block in timber. Using modular timber - even SIPs - would be quick and easy and also not need the deep foundations of a standard build. Is it a simple apex roof ..? Single pitch..? Flat ..??

28” monitor ..! But you can see the bolt head in one of the photos plus it was confirmed.

Welcome ..!! So the industry is busy at the moment so “silly quotes” may be that trades don’t want the work, or you’re in a very expensive part of the country. What sort of size studio are we talking ..?? Do you have plans ..??

So nortmally there would be a top plate on that studwork and the build off it. You’ve got lots in sheer, and nothing stopping twisting or spreading the loads. Fairly crap design IMHO and not one I would be using.

Is that you charge £13,800 inc VAT for the Grant Aerona..??? For a unit that is £4,600 inc VAT..? Does that also include all new rads..? If not, £9,000 install for 2-3 days work is good if you can get it ..!

You’re looking RRP - never pay more than about £40-50 for the Geberit ones apart from the silly one that is about £300...

Unvented cylinder boiler ..?? Do they mean an invented cylinder and separate system boiler ..? Would make sense.

You will need to put a long radius bend on the bottom of the pipe and secure it properly as it will be under load as you flush down the pipe. What’s the full layout ..??

Ok but you will need to vent the stack - You’ll need an AAV on a stub near the WC. No issue connecting virtually directly but watch out for showers etc connecting within the same zone as the WC - you may need to drop the shower down the stack to connect.

Do you mean out of the trap and then into a vertical soil stack ..?

Surely you can see the front door through the wall on glazing .....?? ?

Cup full of frost proofer to a bucket of water.

Your ground floor currently has radiators I expect ..? They are sized for a specific heat loss so first question would be do they work..? If they are sized correctly, and you have no problems then you could assume the boiler will be fine. If you have a 4x3m room with a heat requirement of say 1800W, which would have a radiator of 600x800 double convector. That is sized using a delta of 50°C between room and water temperature - so 70°C. The issue now is that you need to get the same 1800W from the floor, but you have to use much lower temperature water - 45°C max in screed, even lower under floating floors. You effectively need 150W/sqm to be radiated out of the floor at probably delta 15°C. Extrapolate that out to your whole floor, and you need 15kW through the UFH. The boiler will want to kick 24kW out at full power but the problem will be the temperature as you need 70°C for the rads but only 40°C for the UFH. You need a buffer or low loss header as otherwise your boiler will keep cycling on and off as the UFH gets closer to its target temperature. And now factor in that you want probably 16kW into the water for the showers running and you start to run out of headroom with the boiler. I would suggest looking at your options on both UFH and DHW as I think you may start to struggle with that size boiler unless you considerably increase the insulation levels in the walls and the roof space as well as the floors.

4:1 will take a few days to harden off completely but it will be rock solid. Just make sure it’s well mixed and also wet enough - don’t just rely on the moisture in the sand.

20mm conduit snags cables and it’s tiny inside - just use black or grey 32mm waste pipe. Cheap as chips and near impossible to damage.

It won’t fall sideways - it will be a rubble wall that is very strong so just make a strong mortar mix and push it in.

It will also depend on by how much - 6.1m and you will be ok I expect ... 7m and expect full PP time ..!

I think the main issues are that in the 60- early 90’s, everyone had a hot water tank from either a back boiler or “the immersion” that was small, and the memory is of water running out. Then in the 90’s the combi boiler took hold and it was “all you can use hot water” but the pressure was crap. Megaflo came along and tried to fix some of the problem, and then UVCs took hold properly so we have mains presssure hot water, but a fair amount of it. The issue now is switching to new heat sources, and there is always the fear of running out of water as people have got used to the endless nature of a combi, but want the flow of mains pressure, with the economy and “eco credentials” of the ASHP... its the holy grail of DHW ..!

You can get them pre-engraved and are much easier than guessing what is what. Unlikely you’ll get one that takes the 40A an induction hob takes - these are mostly 20A at best.

Eh..?? Is it a Megaflo cylinder then with that really nasty air space at the top ..?? wonder if the installer read this ..??