I'm not a plumber/ engineer but I find this channel a MUST watch. I love watching craftspeople working at the top of their game. We are just about to do a 4 metre extension to our house and I'm in the process of trying to find someone of the same class to sort out the heat calculations/ loss needed - wish me luck!

That's all lovely, but the plant room alone looks about half the floor area of my entire house! I'd wish there was some integrated unit which reduced a lot of the external pipe work etc. and perhaps could sit outside, or in a garage. Even going back to having a water cylinder is problematic for those with small houses.

This video should be called "Gas boilers no longer make sense if installing an HP in a brand new, hugely insulated home with plenty of space for a plant room". Gas boilers still make a lot of sense for your average older home. Just my opinion.

It all depends . We live in a rural area in a 1840's detached house that is not to big but has high ceilings . We have had 3 prices for air source heat pumps they range from £27 k to £32 k . before any insulation up grades . We have no spare internal space for the plant to go and the wall space available in most rooms do not have space for the upgraded radiators. All of the projected running costs are only just marginally below what we spend all ready and will likely be more as the tariffs they have used in the calculations are not available to use. The prices for replacing our 25 year old boiler are from £3.5k to £4.6 k . If you add on the the fact that the ASHP has to be paid up front and the government £5k is not available if your EPC is as lower as ours its just not worth bothering with . ASHP are an answer but the answer to the 1.4 million oil boilers .

I just installed a new gas boiler. I cant afford a air source heat pump as it requires me to first insulate all my external walls from the outside, get new doors and windows and add floor insulation . It’s just not viable for most people here in the UK.

I am very impressed by such professional work, the plumbing, knowledge and experience. Well done.

That pipework and installation is a work of art. :)

On our deep renovation the first thing I did was call the plumber to cap the gas, a month later the meter got removed. Easy for me then with a house full of dead pipework to rip out. Had our heat pump fitted last month partway through renovation, really appreciate all your insights watching your videos this past year.

I’ve watched a lot of your videos and you do a brilliant job, however there are not enough installers yet and certainly not many who fully understand the installation. My two bed property was going to cost 25k for HP, rads, solar and battery, at my age it was a no brainer to install a new combi and some rads for 2K. Now only if I was 25 years younger 👍

Looks great. I agree about the cost on a big complete renovation like that, no brainer. But for the average home when the boiler is end of life its a more complicated question. Also for someone like myself thats a geeky DIYer (i'm doing a full house renovation, so far prob 95% on my own) that wants to do most of it themselves the grant and the vat thing is not much help :-/. Interested in the cooling idea the customer is going for, be interested to see what that looks like if the customer will let you film it. Anyway, great video. Thanks.

I'm prepaired to bet that this man has an extemely high IQ. I have never seen such proffesionalism in this field. His work looks so clean.

Now lets look at a normal 3 bed semi with an old boiler. These high end projects don’t reflect the majority UK housing stock.

That will be £30k please, how do you retro fit to a normal house with no space for a plant room.

On a large renovation like this you are absolutely right, if it's cost neutral then HP is a no brainer. Gas is only going to get more expensive and there is a strong impetus on government now to bring down the cost of electricity. The bigger issue is the replacement market where a new gas boiler is often a distress purchase (after failure) which householders are therefore looking to do quickly at the minimum cost. Sorting out radiators and insulation then becomes something they don't want to think about even if it makes sense in the long run. IMO the government therefore needs to put a strong focus on making all homes 'heat pump ready' and unfortunately the incessant lobbying for hydrogen by the gas industry has made this very difficult.

Total install costs after grants may be still very high compared with a gas system. Maintenance and servicing costs also need to be compared as does the life expectancy of the main piece of kit. If a house is well ventilated and has heat recovery systems the actual heat input should be very little. In fact I remember an experimental house being constructed 45 years ago to a low budget. It had thick insulation, treble glazing and heat recovery. The only heat producing appliance was a gas fire in the living room which only needed to be switched on for a couple of hours a day!

Totally agree, why install gas when as you rightly say the difference is so small and the feel good of doing something towards cutting emissions. As for running cost I suspect with those cops it’s cheaper to run and way more comfortable.. As a retired plumber / Heating installer may I say your workmanship is first class.

Another very impressive install. I’d love to see a follow up video to understand the real world efficiencies after the heating season.

your pipe layout is a work of art, great job as usual

I live in a semi-detached 3 bed house that is on an estate that was built in the early 1930s. So, any quote that includes a complete CH replacement, redecoration, storage of furniture ect, and accommodation for the duration of the project, and can be achieved for £5000, we're in.

Yet again watching your work with properly designed and installed system the case for going with a heat pump gets stronger, very interesting indeed, I already have PV on the FiT but upgrading this system as well with the heat pump makes good sense

Im not a plumber but I haveworked on building sites, im prettysure that floor joists should not be notched to accomodate that pipework, will it not seriosly weaken the floor?

Gas boilers are awesome, 50 years of usage is not wrong…….however I do like this installation, but it is a rich persons game.

Great to watch your videos, very interesting with the details you share. Please keep it up 👍

We have a Dimplex air to water heat pump for underfloor heating and then we ran a line up to our top floor attic for a water to air fan coil. It provides perfect air conditioning in the summer and is honestly one of the best reasons to use air to water heat pumps. They do perfect radiant heating and very good cooling, there are also smaller convector radiators from Jaga that are installed like radiators and provide decent room by room cooling. A technician like yourself should look into this as more people request aircon in your market.

Any recommendations if you don’t have space for a “plant room”. Genuinely interested in one of these for our two-bed maisonette, but a combi boiler takes up no space at all, whereas it seems these need a lot more space (both inside and outside) for an equivalent system?

You can also add solar and batteries to your house when you have a heat pump and run it on that energy instead of grid energy, can't do that with a gas boiler :)

Why do you use copper instead of maybe the Geberit Flowfit system?

How many combis got replaced because a heating engineer couldn't be bothered or didn't know how to fix a simple fault ? Loads. Now imagine whats going to happen when the heat pump develops a fault.."oh you need a new heat pump mate". Nobody is going to want to spend the time to learn how to diagnose faults on these systems. A manufacturers engineer will check the heat pump, but won't touch the rest of the system. I have a six year old gas boiler and its not going anywhere quickly until the heat pump market has matured and is orderly. I still don't think a heat pump will keep my old house warm at anything like comparable cost. The next owner of this house can take all that on as insulating this 1885 property is a real headache. We've done the roof space, we've double glazed and we have insulated underfloor where we can get there. The walls are solid, so it will mean dry lining the whole house, or there is one gable wall we could exterior clad. The one thing I might be OK with is oversized radiators as mine are pretty big, but I need to get a calculator out and do a heat loss/heat output calculation to get a real idea of the requirement. I need to win the lottery and then have a borehole dug, in that order unfortunately.

Great video, thanks as always 👍 Fully agree with what you say regarding the installation of gas boilers especially on a project like this one.

Very nice install. Like yourself, I really hate the “what is the payback” question.

Nice installation and I'm sure it makes perfect sense for a contractors bank balance, however this is a renovation of a house that no ones in a rush to move into and if this is a builder who will sell the project on he will be looking for a return on investment. A couple of questions what was the total cost for supply and installation ?, what's the warranty period, why have you specified such a large installation when you will run the system around 40% capacity ?. Where are people expected to put a cylinder of that size when houses have been built for the last 20 years without emersion heater tanks. what savings against gas will be made ?........... think of the disruption to the average family household with no guarantees........ yeah makes perfect sense.

Very impressive workmanship and women saw a young woman helping , sorry I digress, wow can’t think of anyone in my lifetime that I’ve been so impressed with , keep in mind that I was born that long ago rainbows was only in black and white, if you ever find yourself in Devon please pop in and give me a price no change that just come and do the job , very small house so would be your quickest install on record,

Another quality install (and video) as usual Szymon. Much as I'm loathed to admit it, I agree, gas is mad, ASHPs are the future - for many, if not most properties. Prices will reduce over time, & due to cutting-edge installers like yourself, effeciencies are getting better and better ready for when old-timers like me eventually break into the renrewables arena. Looks like I'll have to change my name, planned ahead & already own LondonASHP domain.

Great work and professional, but an install like that I’m guessing is about 10 - 20k. Well out of the price range for most people regardless of grant.

I have been told by some of my former colleagues that under 5% of the UK housing stock are suitable for ASHP . And half of that figure are new build houses

Amazing to see a real knowledgeable trades person. In Algave in Portugal they don't seem to exist. Let me know if you want a working holiday. 😂

That's going to be such a high performing system! Top work as always 👏. What's the KW rating of the unit you fitted? It looks like a 5kW unit? You should do a follow up video to document the performance and how well cooling works. I think the option for cooling could be a great selling point for a ASHP. What made you go for a Vaillant cylinder? It looks like the Telford HP cylinders have a larger coil and slightly lower cost.

Yes that chilled water will be %100 air conditioning. You will simply need an Air handling unit to transfer the rooms heat back to the water for it to return to your outdoor unit where it will run in cooling mode (reverse cycle) to reject the heat to outside via refrigeration cycle. Then the chilled water heads back upstairs. HEATPUMP = reverse cycle air conditioning normally. Just another true advantage of replacing the old boiler

Your pipework is a work of art. How easy will it be to maintain the system and will it need an annual service. Will fault finding be more difficult than in a gas combi boiler system?

always a pleasure to see the level of craftsmanship, nice one again.

I also agree that ROI is a useless way of looking at it. What is the ROI in having a nice garden double glazing, a new roof, these are simply investments made into your property for comfort, security and aesthetics.

Great video but yet again, these heat pumps are only suitable in a new build situation where all of the insulation and pupework are built in to there latest standards Totally irrelevant to most of the existing housing stock in the UK unless major uplift is also included.

another great VIDEO Keeping external pipework as short as possible is a great design; as you can see from your video, insulate with quality insulation that is VU protected and weather protected and seal all the joints/seal to the heat pump so as not to let any heat/energy out and not let water/moisture in that if it did get in would increase the thermal conductivity so reducing the insulation, heat pump, system efficiency. Sealing through the wall, as you show, is also very important to stop moisture from bridging the cavity and stop all other critters getting in 👍

I've not understood the heat pump method at all. I frankly still don't. But, that whole system looks expensive, I guess care of GOV 5k grant, I'm paying for a piece of it, and I look at the luxury of ploughing under floor heating and the space taken up with all the gear. Saving the planet just leads to insanity. That aside, I want to say great video. I did learn more about it than I have from other sources, and the info and detail was really good.

Just top ! I agree with everything, i’m 23 years install business and i constantly crash in people who calculate cash back of heat pump driving a 90.000,00€ car 😂😂😂😂

Hi Urban Plumbers, as always a really neat install and informative video. Please let us know what the installation cost is for this install, and also going forward the costing for your other installs please. I understand and agree we need to look forward regarding green energy measures to our homes ( which I have done with my existing 1950's property which is now EPC A) . Actually with no one in the property during the install ( luckily so when the tank is faulty and caused significant delay, which if you where installing in an existing property would be unacceptable for someone living in a property at the time) and with retrofit wall, floor and roof insulation it is possible to produce an energy efficient building. The problem comes with retrofit to existing housing stock in the UK, which is generally old and poorly insulated. The upgrade costs for a typical Victorian or Edwardian property are very high before the installation of an air source heat pump system. The typical install costs for an air heat source system including larger radiators etc is as per government figure £12K to £18K which is substantially more than a high efficiency boiler and Radiators. This figure plus any mitigation to the existing EPC value of a property make it very unlikely that those who could really do with benefiting the most would never be able to afford to install an air source heat pump.

Here's where heat pumps are set to be a major fail. My 16kw is happy in the 35° c bracket, I agree with proper insulation and underfloor it is well possible. Now, when I ask for 50°c hot water, on economic, its drawing over 6kw and gets to 47.5°c. Seeing that electricity is 4 times the price of gas it is hopeless at CoP 2.5. What's going to happen is; we're going to be offered very cheap electricity when there is a glut from wind and solar. I have a 4,000 litre buffer with this in mind, in reality I could do with another 4,000 litres. Heat pumps just grind away 24/7 irrespective of the Grid, no use at all for Grid balancing! Available phase change heat stores need sort of 65°c to operate so they are out the picture. You might as well use an immersion heater to make use of pcm's. When I first had my 16kw ashp I pressed the " instantaneous power function " and it showed something like 9.4 kw and it made me wet my knickers, I contacted the manufacturer and to be fair they advised me to stick to "economic" but 6.4 kw is still a hefty chunk at nearly £2.00 an hour. The next major problem I faced was the warranty, for the sake of efficiency I was running pure water. According to the manufacturer, to avail of the warranty it is necessary to use glycol. The next blow was the £300/ year maintenance charge they wanted to drop on me to get to 7 years cover, that's a quarter of a gas bill. Even then they'll do their utmost to wriggle out. So the plan is the boiler I removed is being serviced and will go back in to service to be used as a sort of hybrid system for when the cold winds strike or the ashp breaks down, which it will no doubt. And before anyone mentions it, I was not able to claim BUS and on reflection I'm glad I didn't.

Lovely job and you make a lot of good points in this video. But while it's a straightfoward job to install the system in a house that is practically stripped to the bricks for a renovation, it would be a right head-scratcher if someone didn't want to do that. Thinking about my own place (mid-size semi) frankly I would pretty much expect to move out for a month and put all the furniture in storage for the period, which would add a fair bit to costs. Still, I might one day just have to bite the bullet and do that, I guess.

Let me see, 2-3k for a gas boiler replacement, or 20k for a heat pump, for the vast majority it’s still a no brainier.

There is ONE huge issue that is overlooked when talking about all this ASHP stuff. That is, electricity supply. We were threatened with rolling blackouts last winter which would mean a cold house if you did everything with electricity. Having a gas boiler gives you a backup option (called diversification redundancy in tech speak). So for that reason alone I wont ditch my gas boiler or cooker any time soon. Niec to have options.

That's taking complexity to the next level.

Just one point. I recommend that you carry out an air test on your pipework before filling with water, I did this for years and it saved me a lot of time having to drain down and repair leaks. Air test, then water on.

With Solar Pv panels yes its a no brainer, without them.... electricity is 3x the cost of gas. I have anecdotal stories of high running costs I'm sure you'd disagree with but my point is the argument is a lot closer call. We need cheaper more efficient panels, more installers and cheaper electricty. The future has started but its not quite there yet. Same with electric cars and vans

Yes here we have a typical normal home as usual funking unbelievable.

I put Flexi hoses through the wall all the time, it looks neat, well insulated and it's less fittings, win win if you ask me

Total Bollox I've been installing gas boilers for 40 years and they have never been so reliable and Efficient and gas at the moment is half the price of electricity,a modern gas boiler will heat your home and hot water far more efficiently than a heat pump and having worked on heat pumps on repairs both expensive to repair and loads of complaints from customers on efficiency,heat output and very expensive to run.

wait for electricity prices to jump 400% ... soon .... the idiocy of government ideas is never ending .. diesel cars ... etc DO the opposite of what government advises every time is my advice ... 👍

I love your videos and learn so much from them, thank you so much for all your work on them. A couple of things: have you considered the ‘Vaillant Mono HP connect kit straight pipe’ kit, consisting of a pair of stainless steel corrugated pipes, which can go straight through the wall and which I used successfully on a recent job. I’d like to have one longer and one shorter one to accommodate the antifreeze valve, but that a refinement. Also.. for the isolator I have started taking the tail leading to the heat pump back through the wall and then down internally if possibly and then out at a point close to the pipes which keeps it neater and all cables invisible. Looking forward to learning why the flow rate was so low on your rescue job!

Thanks for the upload. Great video. Looking forward to your next one.

Here here on your return on investment rant! Great install and love the details. Thanks.

Lots of money being spent there. If I win the lottery I'll be flying this guy up to do my installation

I'll wait until I see a whole street of Victorian terrace houses converted to HP before I'm convinced that they are the only solution And I mean a terrace of 2 up/2 down with small back yards that you find north of Watford and not some pimped up house in Islington

i personally would of gone down the air to air heat pump and fitted a ducted system. Then fitted the daikin heat pump cylinder. that makes more sense as the client clearly wants to be able to cool the house as well.

Government says it will happen, without addressing any of the practicalities, costs or available equipment and installers. And its still 1 kw electric in for 3kw out!

Plumber United ! Amsterdam, calling... Fantastic Job, well done

I see you've installed quite a lot of these Valiant systems over the last year or so. It will be interesting to see how reliable they are and with that in mind, please make videos covering any significant faults you get over the coming years... If there are any.

Great install happy with just minimum effeciency as have solar PV.

I’m looking for a career change and have considered trying to get into heat pump installation. Would you recommend retraining in heat pump installations and as someone with no experience in plumbing, where is the best place to start ? I was thinking of attending evening college courses to learn the basics of plumbing first. Thanks 👍

Let's have a think about the Grid, solar and ashp's. I won't use heating for at least six months, possibly more. The summer is when the Grid receives most of it's solar, come late October there's not enough solar to be useful as far as heat pumps go. The winners here are the ones with solar and batteries, they can adjust their Grid use whereas ordinary powered heat pumps will just bumble along regardless. The powers that be tell us this or that solar farm is enough for 20k houses. In reality that solar farm won't supply any houses unless half the daily output is stored by some means. Another thing that's of concern is the amount of power we seem to be importing at present. I watch the stats every day, at the moment it's at 5% and gas is 43.9% but recently imported power has been over 20%. I honestly didn't realise all this stuff when I ordered said heat pump. If I had invested the £16k in 10kw solar and 10kw battery I would have had a ROI of about 13 % whereas I'm encountering massive depreciation. Hey- ho! You,sir are an artist, I love your videos and admire the beautiful installations that your providing for your customers.

Future proofing project done by a real professional. And it makes perfect sense in a multi-£100k house undergoing top-to-toe renovation But my renovation uses the existing gas boiler and multi-zone plumbing. You can buy a lot if gas gir the £10k price differential. Maybe in the future when these systems are near-commodity items and electricity cists much less. Hurry up with that offshore wind...

Thanks for making these videos and debunking all the myths that the media seems to be peddling.

Your correct that no one thinks about ROI on a boiler but then your looking at £2-£3k. An ASHP installation like you just did must run to £12-£18k excluding underfloor heating I would estimate. Even if you deduct the £5k BUS that's a shit tonne of money so it's only reasonable to consider ROI in that situation. I mean I could have bought a decent 2nd hand electric car for that and saved myself more money overall and helped the environment just as much.

Cracking job. But if you dont have nice big space like that its got to be a hell of a job

I enjoy your videos. Would really like to install ASHP plus solar panels in the renovation property I am buying. Did your client dig out the concrete floor in the existing part of the house for the UFH?

Great video and unassailable logic for a new build or complete renovation IF the building is well insulated. Domestic boilers are responsible for more CO2 emissions in the UK than our passenger cars reputedly, yet this is yet to be widely known or discussed. The government will need to push much harder on ASHP support and publicity because guess what; hydrogen is NOT the answer!

@6:30 would be great to see how you did all this pipe work and thought process

Always great to see one of your videos, especially a heat pump one! Given sufficient space to create a proper installation, there really is no reason at all to install a brand new gas boiler in new or heavily refurbished properties, it really is a shame to see it continue to be done. Even if the running costs are comparable right now, they will without a doubt decrease in the future. With so much misinformation currently circulating, do you find you have to suggest a heat pump yourself to customers and correct some of their misunderstandings or do potential clients come to you specifically requesting them?

I am not atrades person but a lover of our planet and being able to breathe clean air, not have a house that could explode as a gas leak had occurred. ASHP is a winner and certainly kept my house toasty warm last winter. I had equivalent of little or no cavity insulation at the time and used 3333kWh to heat the whole home all day. Updated the insulation and a couple of weeks inciated saving 30% of electric use. So 2000kWh or so is estimated for next winter. They work well and I agree all new homes should automatically fit ASHP for heat and solar panels on roof.

Another excellent Video. Good to meet you in Fleet SF today!

I usually don't seeing pipes or cables. I prefer to hide them away. But this pipe work needs to be on display. Very nicely done, very professional, great job. I do have one question. Ar around 8:15 of the video you have you left hand on the controls, right under that control I see some strange looking 4 way valve system. Can you please explain what that is and what its for? Is it some kind of automatic refill for the system?

So i have similar plan to do in my new house now since i still didn't do any consultation with Vaillant i was wondering how the system will work with solar panels, so heat pump, solar panels i was thinking to put massive buffer tank probably 1000L one twin coil and everything feed from that, since we have plenty of sun here where i live but very cold winters - 15c

The upstairs AC loop to the ducted system will also provide dehumidification. What outdoor design temperatures do you use for the heat loss and heat gain load calculations?

ROI is still a valid concept, but it only applies to the additional investment you have to make to install a heat pump, if there is any. Now, if a heat pump is really cheaper to install from the start under some circumstances, there isn't any additional investment to consider, so ROI calculations would not be useful. But, the government subsidies and the high price of gas in the EU are both symptoms of the current political climate, and that may change in the future, so it makes sense for any homeowner to try to set aside enough space to accommodate changes in the future, including a switchable-source system if price or supply prohibits the use of either electricity or gas. Here in the USA, gas is still cheap for the time being, so the only case for a heat pump, at least in areas with cheap gas, is to support both heating and cooling with one system. There are some 1970s houses in my area with resistive electric heat and overhead ducts for air conditioning, and in those houses, there is a strong case for a conversion of the air-conditioning system to a heat-pump, with both heating and cooling capacity, in order to minimize the use of the incredibly expensive resistive heating. But with the way energy prices fluctuate, the only sure bet is on the insulation itself; it's hard to loose on that one.

Heat pumps require space for cylinder, buffer tank large radiators and bulky unit outside some time need planning permission and all costs associated with it therefore GAS BOILERS MAKES MORE SENSE works every time all the time 😄

im doing a renovation for myself and i wanted a heatpump for heating and a gasboiler for water. But i dont have the budget so now i will install a combi boiler and if i have the budget i will install a heatpump. I prefer a gasboiler for hot water bcs the high deltaT and no heat loss if u dont work with a cilinder. Als if the heatpump if broken, i have my gasboiler in reserve.

Have you ever fitted a heat pump system on a typical Victorian terrace house with single brick walls and suspended ventilated timber floors? Do heat pumps still work well (heat sufficiently/ remain cheaper than gas) in these old buildings during cold winters? Considering getting one but haven’t found reliable info on old houses… oldest I’ve seen are 1930s semi-detached houses with double leaf walls with blown insulation, space for a large water tank (often missing from old houses predating modern heating or where combi boilers have been used for years), and plenty of garden space to site one.

I’m still in the gas lpg and diesel boiler over heat pump for off grid , my experience has been really bad with heat pump, I had better heat than underfloor, which in - 30c felt bitter (buffalo last Christmas) but irs exactly this reason I say gas and diesel whether it be biodiesel or in time synthetic, when the powers out people freeze, we had 7 days of negative 20c with no electricity , we were cut off for 10 days due to the sheer volume of snow , if it wasn’t for the fire place I would have been in a bad way, 8 people got taken to hospital in our street due to no electricity and a heat pump refit sadly one elderly woman passed away , in the U.K. we only have to go back to storm Erwin to see similar situation, no heat , and cut off it doesn’t matter if your 18 or 80 freezing cold can kill, the politicians and policy makers forget this, many have never been in such conditions before, let alone had the power off for longer than a day, all it takes off the main pipe is for one bad storm and the grid goes off, this is why I’m advocating that gas and diesel be allowed to continue especially rural Scotland especially with property’s with greater than 15kw energy loss , the cost off keeping the heat going through backup would make it far far more expensive ac it’s not hard to chew through 45kwh a day in sub zero temperatures this is why I say especially for heat pumps Designing for just -2 is wrong and should be for a least -6, which is typical in rural conditions

Thoughts on air to air systems? I.e. multi split systems that do heating and cooling. Especially with the summer temperatures being how they’ve been these make more and more sense and are less effort to install and take up less internal space with no tank required, though don’t do hot water of course

I love your vids mate, im totally with you on this as well

Yeah flexible connections, Yeah there is good reason why they use flexible connections. Perhaps compensate for termal expantions but predominantly dumpen the vibrations, then you dont have a noise conduction from heat pump. Also the distance of flow pipes 20cm to 50 cm would not have any thermal lost considering the velocity ( flow volume ) and pipe diameter. Excelent videos keep them comming its really good and educational.

This installation only makes sense because there is low temperature underfloor heating. When well below freezing outside, an air heat pump with only radiators will struggle, with expensive to run resistance heating having to come in. An alternative to gas, is having the whole all electric. First ensure the house is highly insulated: cavity wall insulated, insulated external doors, triple glazing. Eliminate air leaks as much as possible. Seal up loft and loft hatch. Have cheaper to fit electric underfloor heating. Heat hot water via immersion heaters. Now have solar panels on the roof and elsewhere. Then fit a home battery set. Eliminating a gas meter save £100 per year in standing charges. That can buy a lot of electricity. The solar panels and home battery set can near eliminate buying electricity from the grid, depending on solar size of course.

ASHP is the way forward for new builds as a transitional period providing the electricity to run them coming from renewable sources only. I don't know why, especially when energy prices are always going up, no one is talking about geothermal energy harvest. I'm talking about industrial geothermal plants. Cornwall on its own has potential to provide whole entire UK with energy. Years ago they(so called experts) used to say it's beyond economical threshold. The old properties should have option to connect to the district heating system run by geothermal plants using HIU. This would require major changes to our infrastructure. Sadly major giant companies/corporations and government has no intrest, unless is quick in and out with mega profits. Geothermal energy is endless and fairly clean, with the right scientific approach/investment we could make a difference.

The one thing i worry about is the price of electricity in the future, the UK gird is often neatly at capacity and needs major investment with nuclear to change that which is happening, but i don't think we will have enough to meet the demands as we are focusing on solar and wind which even if we could produce enough with solar and wind we cannot store it to be useful compared to a constant source of energy. Also Imagine 10 years from now if many more people have an electric cars even a slow charger is going to be something like 10kw/h per house combined with the consumption for these heat pumps each house is going to be using way more electric. What will the price of electricity be when its much more in demand, we have seen how quickly prices can rise with any crisis and i cannot imagine the price per kw of electric going down much its more likely to rise and with all the climate change bs they are likely to start rationing it as it will be much easier to do with electric. I would think a solar array would be a good investment long term to counter the rising electricity costs and paired with a heat pump might be a good idea. Also something to think about no matter what they say its not warming every year, NASA's own satellites show there has been no warming for over 15 years, we are likely heading into a little ice age in 2036 i do wonder how well these heat pumps will deal with the cold, last little ice age the Thames froze over :) www.historic-uk.com/HistoryUK/HistoryofEngland/The-Thames-Frost-Fairs/

At 5:33 you used plastic pipe holders. Are they a special brand? I only know the steel ones with a screw at the back.

Interesting project. Love the torque wrench. Would rather have a professional do my plumbing, but want one anyway!

The other alternative would be straight forward electric heating, especially if costs of electricity relative to gas falls. The thousands saved not installing heat pump system should keep you going for a while.

What was the cost?

It struck me that in a city environment, the air available for drawing the heat out of would effectively be that of your own back yard. In those cold still winter mornings, the cold exhaust air will fill up this backyard area until the units dont work! Most city housing is quite cramped with lets say a 250M sq garden (figure taken from Cambridge estimate which is one of the better cities), thats 250Mcubed of air before your unit is totally immersed in cold exhaust. ie, if everyone has one in cities, theyre not going to work on those still/frosty mornings. Doubtful of this, well look at it another way. Cities are 10-15C warmer than their surrounding countryside due to heat leaking from homes. If they go over to heat pumps, this will mean they will be 10-15C colder than current and then add in all that cold exhaust air from heat pumps. My conclusion is that for expensive new builds in the more country areas, they would be good. But for most people in older houses, itl be too large an investment with the cost of ripping up floors etc.

Spend 40 k to get it all working as it should, by redesign of whole house.

Love you and your work, but asking ROI on an ASHP installation is not a silly question