JohnMo

Out of date by a decade or 2. Most of Europe has been running Weather Compensation or room compensation for years and the boilers sold there have to run weather compensation, so boiler flows down to 20 to 25 are mandatory. My Atag, did so once an outside sensor is attached. All Viessmann boilers do plus many more. The British boiler market is just way out of date. You need to be a combi boiler or priory hot water setup to allow low low temps for heating and high temps for DHW.

They are a bird mouth at the ridge beam. Would have to go back through the structural drawings but believe they are angled nails.

I had plenty tell me airtight was a disaster, my house would be full of mould in 3 months. They were wrong. Have they ever experienced a thick screed house in your case maybe not. First alarm bell is So they operate the system by thermostat not WC. Thick screed is glacial in response time from cold. But that is point of WC it drip feeds the floor. A well insulated house is also glacial in response so match each other well. It absorbs lots of energy and that's the point in a lot of respects. It rides temperature swings pretty well. It's a low temperature heat source for the house, it self modulates well. Think screed high UFH is what they are referring to so very different.

Do a Google search on MCS umbrella scheme. How good or bad they are, anyone's guess. Suppose you need to try them, see what they output system wise and cost wise, buffers, glycol, stupid large ASHP etc, move on or challenge, see what the response is.

Maybe get worse before it gets better. Don't the better guys just use the system and navigate around it where needed. Do a justification if required to keep a box ticked. If you can acquire the skills yourself - do it yourself.

Nice use of Imperial and metric units, possibly best to stick with metric throughout. You could easily use posi joust/rafter with that span - we are doing 7m at 600mm centers. But you should be having structural engineer input, not designed by a committee of unknowns.

Not sure what happened to the link https://pirateheatingsupplies.com/product/frv-flow-regulating-valves/ Sold by quite a few places Also found this midsummer-frv-combined-leaflet-web.pdf

@JamesPa - it will make you cry, skip the first couple of posts. https://forum.buildhub.org.uk/topic/45364-ssr-query/#comment-633802

Pretty poor install really. Why a buffer at all, if you are running single zone? Then you can delete the interface, the secondary pump, all the actuators on the UFH manifold. Either bypass the buffer totally or convert to a volumiser (I would convert to volumiser as you have it).

The cone filter is in the room terminal, so as not to allow anything to get in the ducts. Plus suitable seperation between grease source and extract terminal.

Why do you need a SSR to drive a circulation pump?

We actually had no one that smoked, from the trades we employed. Made the statement about no smoking, when they came on site, all said they didn't smoke.

Yep if you don't fit them they don't of perform very well at all. 😁

Good quick start guide, and a sensible ventilation and heating system. Well done. A low heat loss house it's sometimes way more sensible just to use storage heaters.

That's not how it works the grant isn't a fixed value, it's a fixed max value up to £7500.

Designing that could be problematic in the long term as grease is carried upwards and if you are not careful and have suitable grease filters at the terminals your ducts could be coated in grease then dust etc... We purposely did the exact opposite, our extract is the other side of the room, about 4m from the hob. We always have a G3 or G4 cone filter in the terminal, it mops up any grease that may get there and any dust anyway

What pressure is it jumping from? What pressure is your expansion vessel set at? Has it been checked?

We did recirculation, but we hardly ever use it. MVHR does the job 99% of the time. If we have a few pots boiling, I may put MVHR on to boost, but that's a couple of times a year. Good hob extractors aren't cheap. If you go recirculating the charcoal filters need to be the regeneration type.

I would go back to basics, look at the heat loads for each room, map out the kW needed for each radiator and assess bottlenecks and then have a targeted plan of what to change. Did see these for dialing in the radiator flow rate rather than guessing what should go through it. gad_source=1&gad_campaignid=22603472091&gbraid=0AAAAA_uQOsJMNQDNZy3kZPgMIc8u_tP-t&gclid=CjwKCAjw89jGBhB0EiwA2o1OnxCGb19yDCsYXChkOKd1KPrPTzeaei0zYmwFhbRlHwdSlPl7y2oQnRoC4ogQAvD_BwE Cool Energy seem to be well priced

Your either a skinny one already or you need to work harder. So get a move on. Too much time sat in your bum writing on buildhub. No buildhub for me while I was building.

Start with basics zero cost options. Have you tried balancing the system? Water will take the easiest route possible, so if given any chance of short circuiting the last rad it will. Vibration through pipes needs a flexible hose at the heat pump on flow and return, doesn't need to be any particular shape.

In general yes, but you need a 3 port diverter, not a mid point valve - MoMo are not spring return generally. A 3 port diverter, this driven by the ASHP controller. Directs water to DHW or heating system. Fan coils - are really just a radiator in a box. But put out almost zero heat without the fan on. So no harm water flowing. They do not need any valves except for isolation valves. What fan coils are you installing?

CT1 either end of the hole. Internally allow for a skim of filler if you see the pipe, otherwise CT1. Ideally the hole should have a liner. So CT1 in place and CT1 the gap for the pipe.

Are you sure you are calculating the pressure drops correctly. Your head loss on UFH isn't large as all loops run parallel to each other Easy don't use home automation. But control single for a 3 port valve is power off to heating, power on for DHW. So not complex. You wouldn't send DHW heating water through it, but UFH water no issue, better than stagnant water 6 to 8 months of the year. As laid out you are powering 1x valves at 7W each nearly all year and another some of the year. Let's say 10W x 24 hrs a day and 365 days a year, so about £25 a year. A 3 port diverter would take power only when doing DHW a MoMo type diverter only uses power while moving, so almost nothing per year. Most do. But do you really need it. Mine has those contacts and they joined. So always have a demand for heat, this doesn't mean the heat pump runs, just that it can, the basics are it's programmed to run WC. A normal WC curve will start at say 20 degs outside and lowest flow temperature from ASHP. But this can start at 10 degs outside if you want, I'll to stop possible over heating at warmer temperatures. The heat pump then senses return temp and fires up if needed. My heat pump hasn't fired up in the last 2 days, because it's sensing the return temp hasn't dropped far enough to require additional heat heat. If on a low time of use tariff you can play games with above. 1. Batch charge floor like a storage heater. 2. Program a second set point so you have WC in background but force charge floor at higher flow rate in off peak periods, so heat pump backs off when return to normal flow temperature. 3. A hybrid approach to batch charge in milder weather but transition to full WC as temps drop. Good for heat pumps that are a little to big for house. None of this need much smart stuff to do.

What are 4x valves doing and why? Do you really need the UFH pump? Simple way is interlock heating and DHW 2 way valves one open the other closed or wise versa, or make it even simpler a 3 port diverter. Then run everything on or off. If you don't want fan coil fans on for heat just set a target temp in the controller of fan coils so fan doesn't come on. Then set a WC comp curve to suit for heating and most likely a fixed flow temp for cooling. What does your system look like? An sketches?