JohnMo

Just negatives, simple solution is a decent tariff that doesn't inflate day time prices

My reply was to the above. A few steps to make heat pumps viable to the masses without ripping out functional DHW systems. Immersions may not the best or only solution. Time of use tariffs, come in many formats. E7 is one, and they don't have to be and could be mandated so they are not inflated prices during the day. Octopus flux export, gives you standard rated in the day and discounts at night it also pays well for exports. Plenty of criticism, no practical solutions voiced, or did miss them? While I was ducking!

So you are saying millions are wrong using E7. People on here still use it and are quite happy. You can't get an installer or manufacturer to agree with you. So chat all you like, nothing is going to change. Your goal isn't going to get realised without a pragmatic approach to allow everyone an alternative approach to a new cylinder.

Seems from this thread and others, some aren't happy removing their cylinder, so the option is limited, 0.7m2 and and heat pump, equals lukewarm water. Even E7 will give you a price equal to a CoP of 2 and was ok for millions for many decades. Do don't see issue. So what's your better solution if you don't want a heat pump cylinder.

Decision made 1 x 5.5kW hybrid inverter on the house array (3.1kW) with 10kWh of batteries. Have chosen Sunsynk for the inverter and batteries. The Sunsynk inverter will push any excess PV to the batteries if they are full excess will be pushed to the immersion. Pretty much out the box solution. The other PV array will remain as is. Little efficiency loss, but... To much digging and running cables to do anything else, that is cost effective. I have installer lined up to install begining of September. Octopus are having to install a new smart meter, so no smart tariffs until that is fixed.

A couple mandatory requirements wouldn't go a miss All new builds to have electric only heating and DHW. End user chooses or architect (in most cases). All planning applications will only be approved with install of minimum insulation levels, and removal of any carbon based boiler system. If you don't want to do that, then all your planning applications will be refused. A simplified permitted development criteria, a simplified noise limit and placement guidance. No need for planning unless on a site of historic importance (they would be exempt from all the above and have their own rules and regs). No VAT on the purchase of electric driven heating equipment or heat pump specific cylinders. This includes standalone purchases or as part of an install package. A 50% tax rate + VAT on all non electric heat appliances and all cylinders without a prescribed coil area. Gas, LPG, biomass and heating oil price uplift to 50% of electric price per kWh. So 30p for electric, 15p for gas, heating oil, biomass, LPG per kWh. Option for DHW heating, via immersion and existing cylinder; Willis heaters are cheap and easy to retrofit to any cylinder, or replace with heat pump suitable cylinder. Electric Tariff available for either option. After that the market would sort it's self out. Remove £5k or £7.5k (Scotland) grants.

But why would they and where would it stop. Even if they did that's still between the installer and manufacturer not the end user. So taking it step further even if a manufacture say yes, you can install on any cylinder, the installer /designer has to carry the legal can, if it goes wrong and they get multiple call backs, because it is rubbish at heating. Any bad advice given by the manufacturer is between the installer/designer and manufacturer, not the end user. You have no contractual relationship with the manufacturer. So likely hood of anyone agreeing to install a heat pump on a small coil cylinder is remote at best.

Legally your contract is with the installer, they have full legal responsibility for all that they are employed to. And if MCS that is full design, install, and commissioning. If they take advise from the manufacturer that is legally nothing to with their contract with you. That manufacturers responsibility is between the installer/manufacturer and nothing to do with the end user. Your recourse is via the legal agreement with the company you employed.

Here's some Viessmann ones also Download - UK Schematics.pdf

Cable size depends on distance and load required. Plus acceptable voltage drop. If you don't know get advise from your electrician. Charging car batteries and a fair distance equals a very big cable

Not experienced anything like that, but we only have a minor scaling issue really. To get WC, you may need this control for the boiler, plus the outside sensor. https://www.worcester-bosch.co.uk/products/boiler-controls/directory/greenstar-sense-ii-weather-compensation-control You then have TRV's on the rads set a couple of degrees above the normal room temp you want. No need for internet thermostats. Boiler just to ticks over at lowest temp possible. You should get really good efficiency.

I put in manifolds for hot and cold, lets you isolate a single room, without isolating everything. Good at the end of the build for doing rooms and bringing them online with others isolated. You can also run 15mm from manifold to the room. Insulation, I did insulate or run within insulation for the most part. Do you have long runs? if so consider hot water circulation, if you go this route, hot water pipes all need good insulation.

Or BWT combicare. Cheaper, I have been using for a couple of years no issue. Get them on Amazon next day delivery. Depending on what boiler you have chosen, I would take a look at the manufacturer own controller thermostat. You should also make sure you can run weather compensation, and have the function in the controller to have load compensation. The weather compensation will give a flow temp to match heat required by outside temperature. The load compensation will compensate for any miss match in the running curve of the weather compensation. Wouldn't touch so called smart boiler control with a barge pole. Unless it's from the boiler manufacturer.

Thermal store isn't any to do with any of the plans above, nice and simple for the boiler, just heat the cylinder, it doesn't care about anything other than the cylinder. But no use for the heat pump, as you need a second cylinder for DHW. Do the individual zones call the boiler for heat, they should just call for a pump to start, to draw hot water from the store. The store thermostat does the calling for heat, independent of the heating system.

Is any long warranty worth it. Car manufacturer give huge bodywork warranty, but small print states the body has to inspected and corrosion treated replaced as needed etc. Look at the service book this section is rarely signed off by the garage when you get a service.

And would imagine if the efficiency was worked out it would be hideous, lots of small zones; boiler short cycling here we come. Running weather compensation you would remove most or all the zones and have single point control thermostat and with radiators have it set to weather compensation with the addition of load compensation to compensate for a slight miss match of heat load and demand.

Here is a snippet out of my Atag gas boiler manual. This is X plan. 3 way wired back to the boiler, the boiler then knows what temp it fires at. ASHP are the same configuration X plan.

Have you pointed to the correct link, that's about priory hot water, instead of S and Y which I also think should be banned. Opentherm is a different subject again. W plan is just really a 3 way diverter, instead of mid point valve - X plan gives you two distinct flow temps. One can be weather compensated normally.

If you have UFH the system design is done basically. Just a matter of kW for the heat pump size, if your have loads of zones, install a buffer (but a two port in the return line). 3 port valve and cylinder. 6kW can get away 22mm copper pipes as long as the run isn't for miles, 6 to around 10kW 28mm primary pipes. Keep an eye on eBay, my ASHP was £1300 delivered (same thing from Viessmann, currently reduced to £3300 from £5200) https://viessmanndirect.co.uk/Catalogue/Vitocal-Heat-Pumps/Vitocal-100-A, The same person I bought my ASHP from, also had pre-plumbed cylinders for £6-700, @Jenki I think bought one.

Some discussion here also https://www.greenbuildingadvisor.com/question/lunos-e2-hrv-and-lunos-e-go-hrv-fans

I used a Sarnafil S237 membrane, it's mechanical fixed, all fixing hidden under an overlap then fully hot air seam welded, with a standing seam welded on also. No issues so far. We paid £14k fully installed in early 2021 for about 200m2.

The whole idea is it's on the plan, sorted, you have planning permission. There no permitted development rights for anything while a property is being built, until approved and signed off. While a build is under progress it has to be completed as per the approved drawings. The heat pump location looks like I took it from the Scottish version of permitted development rights https://www.gov.scot/publications/guidance-householder-permitted-development-rights-9781780456836/pages/8/ But this English site says front wall. Less prescriptive.

Couple of comments A new build has zero permitted development rights, until after the completion certificate is issued. So no. That also states it must be on the rear elevation in a conservative area, within permitted development right, which is relevant here anyway.

You need some bells and whistles to install their heat pump if you are not using their cylinder, a heat pump module and their controls in addition to the ASHP, or an interface and 3rd party controls.

I did an image search a while ago and comes up the Chinese selling site. (Forgot the name). Never heard of the maker before, but it half the price from China direct