JohnMo

Ok, obviously our answers not good enough, I won't bother next time

I posted all the manuals for this last week (ish). Have a look under underfloor heating section

Or use Pert-al-Pert. Then you can also find the pipes if you ever need too, because of the aluminium layer. Should only real 16mm for good balance of energy delivery and limited heat loss, compared to smaller pipes.

So now all you need to do Delete buffer Delete secondary pump Delete all the actuators Delete the thermostat -no your controller has one, but shouldn't be needed on weather compensation. Delete wiring centre All stuff your installer charged you for to buying and installing and it all adds to inefficient running.

Are you not making work to prove a point? Either have window or wall trickle vents - with humidity control - Job done. But no trickle vents in wet rooms. And with internal door undercuts to allow air to flow as required.

Not sure there is right or wrong answer just preference. We have done both before and after kitchens, really makes no difference.

Air takes the easy route - so PIV, will just feed the dMEV, no ventilation in to dry rooms. Not a good idea. Either pick PIV or dMEV not both. Doing away with trickle vents is a bad idea - have trickle vents just install a self regulator that adjusted for humidity then you get the right venting the right place. You plan is is well ventilated hallway and wet rooms. But no ventilation, in dry rooms.

Was pushed a heat geek video, on their marvelous zero disruption AI quote system and install service, so out of interest thought I would give it try. You put in your address, and a few seconds later out pops a quote - very quick, very easy, you can then accept the quote and move on to a £250 full survey etc. So it has my floor area, so must have access to EPC database etc The things it has wrong - I need to upgrade radiators anything from 2 to 13 depending on efficiency target. I have UFH? My heat loss is 6.7kW, it's closer to 3.2kW at -5. They would install a 10kW Vaillant heat pump. I currently have a 6kW and it's huge, why would I need a 10kW? Then there is the cost - £16 600! Like heat geek for it's ideas, but this is a bit of a joke. The heating requirements in the EPC isn't very different from actual, but suspect they choose age of build, foot print and apply a rule of thumb. Anyone else tried?

Not sure I would do series, think you are just adding complications you don't need. The WC curves will be very different and the ability for the system adopt automatically none existent. Run then as a parallel system all one zone. In a well insulated house bedrooms will borrow heat from downstairs, but the radiators will also add heat. If the bedrooms end up too hot just switch off the bedroom rads or balance the flows down to get a comfort balance. The above keeps dT sensible, series doesn't. 8 to 10 dT may cause the ASHP to back off or increase flow rate depending on control logic.

Take away any eco stuff for a moment. My story, installed gas boiler on new build. Suffered overheating in shoulder seasons and summer, realised the only cost effective way to cool was A2A or A2W via floor. Already had UFH, so A2W was the least disruptive. Saw a bargain ASHP come up on eBay and bought after a few calculations. Initially installed as ASHP to UFH and had hybrid DHW via boiler. Few iterations had a full hybrid system. After a heating season running hybrid, did the calculations, having gas was costing me more than a £100 a year compared to ASHP alone. Gas went this year. In real cost terms (now on Cosy tariff, with battery and PV) my heating/cooling and DHW will cost at least 50% less than gas heating and DHW did. In summer DHW is either PV through ASHP or cheap rate. All heating is cheap rate, all cooling is PV powered. That is why I said fossil fuels boilers should be banned on new builds. I should have included renewables should be mandatory also. More save people from themselves.

Op has already spoken about huge cylinders, so obviously has space. That really is never likely to occur. As much as the right thing to do, is to ban gas or oil from any new house. You just don't need fossil fuels. So don't disagree with you at all. But being pragmatic, you do a powerful combi with lots of turn down, or big storage and suitable boiler. The big storage allows a more modest boiler, turn down doesn't matter, as you do the storage as a thermal store as @Nickfromwales shows above, then you can draw the heat for the heating that without having to manage modulation.

Just looked at that boiler and it looks pretty good, goes down to 3.5kW and does full weather compensation. Seems to tick all the boxes. Add a small cylinder upstream of the cold water to keep temperature rise low and consistent all year. Should flow very well indeed.

Most combi boilers are already huge outputs, great for DHW output but utter rubbish for CH especially in a new build. You have to balance the minimum output and max output. A boiler kicking out huge DHW flows is great, but if it spends the next 22 hrs short cycling that isn't so good.

Some reading I did a similar setup - you don't need huge boilers - could flow enough to run 3 showers on the edge of stability, 2 with ease. Canetis-SuperFlow-Product-Sheet-WE-050318.pdfCombi-SuperFlow-White-Paper-v1-2-4.pdf Setup is sold by Alpha Boilers

Non condensing oil boiler is circa 60 to 70% efficient. A modern condensing boiler circa 90% in a well setup system. A simple single zone ASHP around 400 to 450% efficient. But flow temp is king with ASHP.

Suspended floor you need lots of insulation as downwards heat loss is huge. If you have a solid floor you either insulate very well or do zero insulation and use the ground as a buffer. But the zero insulation needs to run the full heating season to be efficient. Lots of insulation is a U value circa 0.15 or better To do well is difficult as a retrofit. To radiator is just easier. Fan coils uses water as the heating medium Aircon uses refrigerant. But similar otherwise. But an ASHP will do heating, cooling and DHW.aircon just heating and cooling, not DHW. Depending on lots of factors, like flow temperature, but pretty similar or very different.

If they don't need to go across someones garden or land they possibly wouldn't - you just end up paying more for a longer route. They are unlikely to reject saying its too expensive - they will not care how much it costs. it's your money they will use, not their own.

Pretty much as explained above. So assume your heating power at design temperature is 3kW. Now to do hot water you need to allow 2 to 3 hrs for hot water production depending on cylinder size and usage. You now work on the basis that the heating would be needed for 24hrs at 3kW, so 3 x 24, so that is 72kWh. So in a 24hr period you need to produce 72kWh. However as you are spending say 3 hrs on DHW you now only have 21 hrs to produce 72kWh. So now we divide 72 by 21, which is 3.4kW. So the actual size of heat pump required is one that produces a minimum of 3.4kW at -3 degs. However the biggest consideration is modulation. If you need 3kW of heat at -3, at the more average winter temp you only need help that so 1.5kW. So the ideal heat pump is one that can modulate down well. The better the modulation the more time the heat pump spends running and the less time on standby. You shouldn't need to adjust that figure as it's calculated from your inputs.

But the OPs non condensing one won't be cheaper than anything to run. Plus it's at least 30 years old.

1. Either will.be good enough 2. You need the area exposed to the internal temperature. So a vaulted ceiling wouldn't be the flat area, the it would be whole area you can see and touch 3. The floor area is the area touching the ground. 4. Bottom green box in middle "total heat loss" You need to allow room for DHW.

You have paid someone a small fortune to install this, get them to sort, stop messing.

OVO are trying to raise funds and possibly merge with Scottish Power, as they cannot meet the financial requirements of OFGEM.

The purpose of this membrane is to stop micro bubbles forming when the cement in the screed reacts with aluminium foil on the insulation. The reaction gives of hydrogen. You do this membrane before the pipes and just clip through it.

Think you need to start your own thread, not sure how painting masonry walls fits into painting wood. External paint may require UV to keeps it's colour. May just turn yellow without it.

You need a certain distance from road edge to be roads spec. Think yourself lucky no visibility slats have been thrown at you. Our previous house needed a 25m and 15m long 2m high stone wall taking down and rebuilt, like for like as we were in a conservation area. £3k is small beer. Do it properly or don't bother.