JohnMo

Possibly need a little more information. So what is your exact floor buildup?

Couple of different things being confused here. Your DPM will or should be below the insulation, so if you have a suitable depth of insulation 150mm of PIR or more it will not be pierced. The plastic membrane between the insulation and the screed, where you are attaching the UFH pipes, is there for sepereration of the insulation and screed. It stops a chemical reaction between the aluminium and cement in the screed.

If you are NOT doing it yourself and paying for someone to do it, you really need to choose a contractor that is comfortable doing the build method you want, or choose a build method your local workforce are comfortable doing. Mix and match is usually disaster. I did lots of our build either myself or was there every day and all day if I had contractors on site. Insulated raft or do you mean passive slab? We have a combination of traditional footings, but bigger and the front wide ones are all reinforced (see attached) with an upstand of concrete blocks, insulation and aircrete blocks , this then infilled with a steel reinforced slab, insulation, UFH, then more concrete to form the floor. Horses for courses. Just have a good plan of what you want to achieve, then move forward based on the first paragraph.

For a filler I used the brass assembly at the bottom of the silver vertical pipes. Fill and Flush Valve - 28mm from BES about £55. Worked well. For expansion you need to check if one is already installed in the ASHP, but possibly not. So you will to size based on system capacity. I used an arm coming out of the wall, which had all the control stuff and bleed already included. Flamco - Contra-Flex Heating Expansion Vessel 12 Litre FCST 012 Tesla T-BAR Expansion Vessel Fixing Bar Kit (T-BARKIT) from unvented components £60 delivered for both. For the 3 way diverter I used eBay, plenty of good deals on there.

Not sure building control care as long as you have a sign off cert from the electrician. Just seems more stuff to go wrong and scratch your head over in 10 years time when it's all old hat, the company no longer supplies the replacement parts.

Panasonic are supposed to be good, but an oversized or undersized of any make will be a poor performer. It really more important to install well that makes all the difference.

So how much energy is your heat source using to heat the cylinder contents up?

Just started a new thread. My cylinder is equipped as per mixergy concept, the heat transfer efficiency doesn't look very good. https://forum.buildhub.org.uk/topic/33175-heating-cylinder-via-heat-pump/

Been doing some experiments which are still ongoing. During the tests below cloudy sky and PV generation 0.5kW throughout. Heating a 160L cylinder with ASHP from 42 to 45, I seemed to use around 2kWh of electric to drive the heat pump from main import meter. The heat pump is 6kW. The theoretical energy input required in the cylinder is 0.6kWh for that temp rise. So on the face of it doesn't look anywhere near efficient. I my be getting good efficiency at the heat pump end making hot water but the conversion to hot water in the cylinder not so good. Experiment 2 Boost cylinder immersion on for 15mins. Temp rise recorded from 45 to 48 for that period. Electric meter didn't change reading. It's a 3kW immersion, so should have used 0.75kWh. Immersion seems to give a close approximate to energy in verses energy out. The heat pump seems to loose out in its conversation when transferring heat to cylinder. What are other people finding with their systems?

I use mine a couple of hours in the morning and the same in the evening, I have have it set at a low temp, so it not a cold hand wash in morning, more a warm one. In the evening when showers are more likely in our house, its just keeping the pipes warm, so hot water doesn't take that long to arrive. So costs are more like 4 x 0.027 x 0.34 x 365 = £13.40, possibly lower

Or a pump like this, it has an built-in timer and thermostat. You set the times you want it on and the thermostat lets you adjust the temp, it then only pumps until it sees the temp required etc... https://www.anchorpumps.com/lowara-ecocirc-pro-15-1-110-u-1-2-bronze-circulator-with-timer-240v?gclid=CjwKCAjwx_eiBhBGEiwA15gLNzmQxn4_qdy-fiCkBdn3Tc0KHsKkZP2lE_2PoClhsJwYmVXOy7r5QBoC9dQQAvD_BwE

I generated the best of nothing today due to lots of thick cloud and fog, we are having rubbish weather.

The open area of the filter will be much smaller, than current filters, (assume not F7) causing a large pressure drop, you may have to up the fan speed considerably to get the same flow rates as you currently have.

My second option was a Grant ASHP, can be had quite cheaply if willing to haggle a bit. I was quoted around £1700 for a 6kW one including VAT and delivery. I would have installed more like for Chofu instructions than the Grant ones.

Don't fall in to the assumption I did, you need listed building consent prior to starting any work, as well as planning consent. They are very different things and different paperwork and departments. And you have to tell them about internal stuff as well as external stuff you change, even if it's normally permitted development. Check out listed building regs also, as they trump planning regs.

Daft question do you need disability access?

I dumped 3 and wife dumping EE, our best signal download is Vodafone, so depends on site

We have textured slabs and the low spots have small puddles, even though there is a continuous slope away from the house. If I wanted every last drop to drain away the slope would be pretty big. To check you need a spirit level - a nice long one.

From openreach website Usually a wayleave is an ongoing agreement without an end date. So it’ll continue to apply to the apparatus it covers, even if the owner of the land or property changes.

I got my Maxa from eBay, the seller is linked below, they sold a couple on eBay and when I researched them they seem to be plumbing wholesale or similar - Beneath heat ltd, postcode CM15 0CH. Postage labels were still on the package direct from manufacturer to them. Do some digging contact direct. https://www.ebay.co.uk/ulk/usr/brownindustries2012?mkevt=1&mkpid=0&emsid=e11051.m44.l1181&mkcid=7&ch=osgood&euid=f18cb42d2e7649cf81f13c195cf0c5a6&bu=43030544433&osub=-1~1&crd=20230114082519&segname=11051

If it's already there, you will not get anything, so don't hold your breath on that one. Any money I believe would go to the original land owner and never to you. I contacted BT, they contacted openreach and they provided free of charge the cable to put along the road from the pole to house circa 100m for own trench. However due to the super slow rates, and no fibre anytime soon, I just do it all via a 4G modem. Works fine, no connection fee, sim card on unlimited data, sorted.

For the kitchen living room, use the coldest room as reference or even the hallway, then balance the UFH flow rates. To make a room heat up more, you increase flow rate at the manifold, by adjusting the flow meters (say 0.5 l/min at a time) for the loop or loops in that room, to decrease the heat output you decrease the flow rates. Do a small amount each day.

Every day is a school day. To make sense of the attached you need to know your calculated heat loss, then divide that by the floor area, that gives you W/m2. then its just a matter of drawing a straight line between your preferred flow temp (high 20s to low 30s) and the W/m2 and that will give you ufh pipe spacing you need as minimum

Hallways are generally an area where air passes through so are ventilated by default. Example air is supplied to a living or bedroom, the air is extracted in a wet room, so it is likely to pass through the hall on its way to the wet room. Also halls are not spaces where damp air is generated or people are present for long periods, so additional ventilation is not needed.

What size duct are you using?