JohnMo

It is huge and running on speed 2, so not a small energy input.

Or could that be a volumiser, and do away with hydraulic seperation and additional system pump. Currently he has pump in boiler, pump the other side of the LLH, then one on each UFH manifold - lots of pumps.

Not really as they are all different. But a single zone system looks ok. I needed about 40L to keep mine happy, small volume equals short run times. You need to read install instructions to get the correct details.

Depends if it doesn't or does shrink really.

As it says in the video, normal caulk shrinks. So you end up with cracks every couple of years. Then you need to think about painting again. Bigger the gap the more it shrinks.

10% is a little low, just had a look at my EPC and 20 to 25% is a better value for the increased heating requirements for DHW in the 6 winter months, as an average, compared to 6 summer months, as an average.

Like most jobs simple enough, but time spent doing this, is time not spent doing other jobs. If your interested in learning all about it, do it yourself, if not really that interested get someone to do it for you. But make sure balancing and commissioning (with calibrated flow meter) is included and full payment not made until complete. Choose your battles!

Just keep your hand away from where you nail. My second day, I held the wood close to where I was nailing, the nail hit a hard knot and went at 45 deg, through my finger. A tad sore, pulling my finger of the nail. Good job I had some masking tape in the van, to use as a plaster.

Before you go the road of making mods Check your summer gas usage, add 10% to that usage, to account for the colder mains water coming in during the winter. That is your DHW usage, convert to a month usage. Any changes you make, will not change this figure. Now subtract the calculated monthly DHW usage from your winter gas usage. That figure is how much your heating is costing you. You could save between 10 and 20% on that gas cost, but if you don't like the feel of the house on WC you will save nothing. Do you maths. Is it worth it to you?

What lie they don't say anything really except it smart - smart just means internet connected. Highlighted bit says a radiator valve doesn't takk to anything.

Read a new article last night stating that the Octopus tracker calculation method was changing, so prices were going upwards quite soon.

I have stayed variable, rather than fixing and being stuck on a higher rate. All things being equal, rumours have it prices are due to reduce over the next two quarters.

Not really enough information to answer the buffer question. UFH is it zoned if so what is the smallest volume of water? How far from heat pump is the cylinder, it easy to run a cable between the two? Can you provide the minimum stated system volume required for ASHP? If more volume is required a volumiser may be a better bet. Basics are ASHP 3 port diverting valve - one way to cylinder (normally closed) the other side to UFH (normally open) Heat pump cylinder, ideally with 3m2 coil It is normal for the cylinder to use a temperature NTC probe to measure the actual water temp, although most can be configured to use a volt free on/off signal.

Out of interest what flow temp do you use?

Flow temp is related to pipe centres and output required. Timed heating is never low flow temperature, weather compensation can be and most likely.

The main difference between operating in weather comp mode and timed heating mode is floor temperature. WC floor will be cooler, this does several things itself. It self modulates output - the closer the floor surface to room temperature the quicker and more immediate the change in heat output. Heat output is a calculation of surface area and difference in room temp to floor temperature. The smaller the differing temperature the less the output. So room gets solar gain, floor gives off less kW of heat. This in turn gives the boiler a higher return temperature so it modulates heat output down to match. The opposite is also true, room cools, boiler gives a higher output, because return temp to boiler is lower. Setting the correct WC curve will automatically switch off and on the heating also, as return temp remains too high once you get to a given flow temperature - this point is adjusted house by house and is curve dependant. Radiators cannot do this nor can high flow temp UFH.

Load compensation is flow temp altered with respect internal temperature, (quite immediate changes), where weather compensation is with respect outside temperature (more an average outside temperature). Load compensation and UFH is not a match made in heaven - tried it it was awful, temperature yo-yo.

I started in the same place a few years ago, then realised I really wasn't getting what I expected. After that I learnt and started to drive what my expectation were. I actively reviewed and commented on every document, as would as a client within an engineering project. Learn and fully understand things like kW is and the difference to a kWh - sounds easy, but you would be surprised how many mix up the units. Also understand U values and R values and the difference.

All I will say is get ready for lots of wasp nests. Ours has lap joints and wire mesh everywhere and they still find their way in behind.

New build house, with decent insulation and airtightness. UFH pipes on 200mm centres generally, do 150mm centres in bathrooms. No buffer or plate exchanges 3 way valve to divert between UFH and cylinder. 3m2 coil cylinder around 250 - 300L Most likely a 6kW heat pump would be fine, based on heat loss calc. Our build was completed with gas boiler, but added an ASHP last summer. Heating this year NE Scotland, has a couple of weeks at or around -7, with zero issues. Heating costs during the really cold period is more expensive than gas, but during less cold cheaper than gas. My self install cost around £2k as a retrofit. UFH materials were around £1k and it took me alone 2 days to install. A cylinder is £1k ISH.

Gee you have deep pockets, and at those costs you should be doing a mansion. Your house is slightly bigger than ours. I am running a 6kW heat pump which is oversized. Full retail price is around £2.5k to £3.5k depending on brand, you need a plinth to stand it on and a couple flex pipes, power and coms cable and that's the external work done.

You need to add to this how and when you heat the cylinder, and how your house reacts to the heating being switched off on a cold day. Also if you are using standard rate electric a time if use tariff. Taking 90 mins off heating could be fine, in some cases in many you could get 3 to 4 degree temp drop in the house, which takes all day to recover on WC. In that case big coil and a few small tops would be better spread over the day. My 210L cylinder with a 3m2 coil, takes 35 mins to reheat to 50 deg based on a standard thermostat differential, from a 6kW heat pump. It generally does this twice a day. With a coil half the size, you could spend a lot of time not heating the house.

They seem to work, OSO use a similar sized coil also. I get one with a 3m2 coil, a Gledhill one badged by Ideal, comes with a 3 port valve etc. and was about £400 cheaper than the Gledhill one, although exactly the same.

You haven't said how big you service void is? you need about 50mm to get lights in, but if you just want cables you only need about 25mm

Main thing for me is would it run the house or just a couple of circuits if mains suffers a power cut. Does this?