JohnMo

You seem to get penalised from what people say installing a heat pump, so who knows?

If that's the case something is very wrong with the system. My install cost just over £3500 in parts, so was eligible for £4k cash back, if I went through the grant. Don't think so.

All correct, but point is I am spending only 15 to 30p per day on DHW, if I averaged a CoP of 3 it's 5p to 10p. So between £50 and £100 let's call it £75. It would about £28 on a heat pump. So £47 cheaper doing a heat pump. If the difference in cylinder price is £1000 you have a 21 year payback just to break even. Also like that during a cheap period I can heat the house for the whole period and same when cooling instead of switching over the heating hot water when you need actually need the cooling on. Of cause you can spend less than the grant, but you can only claim what you spend, it's not a heat pump and free holiday scheme. Not sure you claim for your labour, as there is no charging mechanism for that, unless you are business. If you did you would be due employer and employee NI and income tax. As @G and J says possibly he didn't really mean what he wrote.

The implication is most likely correct in theory, but reality for our system is our electric consumption/cost hasn't changed enough to really notice, especially as one of the heats is done in the day when I have solar to pick up the cost. Interesting I was talking with a friend, he has a system oil boiler and switched over to immersion only heating DHW a few years ago, mainly because he didn't see much difference in running cost. Wife is also happier as she didn't like the not really hot water water generated by the heat pump. He has a young family (oil boiler) - there are two of us. Can the ashp recharge quicker than immersion? Depends on the output, but our 210L is generally charged in an hour or less with immersion (heat twice per day), it took that long also with the a 6kW heat pump - not tried now we have a 4kW (installed in January). A heat pump will slowly ramp up temperature from as low a flow temperature as it can, here is a typical night time reheat (our 6kW ASHP) - was 8 degs outside. It took an hour and would have heated cylinder to 47 degs. Used 2kWh. Plot showing cylinder temperature - Last night I reheated cylinder, it starting at 4.30am and was finished at just before 5am and then around 1 hr later ran for a further 6 mins, an hour later another couple of mins, so all up just over 3kWk - but cylinder was at 58 degs, not 47 degs.

Just a simple programmable timer for DHW - stand alone system. Generally you are better exporting solar, but I do get some periods on Agile where export is almost nothing and if you have excess solar, ideal time to dump in to water Wouldn't advertise you made a profit, as you an the umbrella company are defrauding the tax man.

Just buy it yourself. Direct UVC cylinder, heat during cheap rate periods. Direct cylinder compared to heat pump cylinder generally £1k+ or £2k cheaper than Mixergy and Heat Geek ones. Plus it allows you heat house and DHW in cheap periods. Price difference buys a lot of cheap energy. But from switching for heat pump heated to direct I haven't noticed any difference in overall cost of electricity. You will most likely have UFH anyway. Then you just need the ASHP. I paid £2k for mine. You also have the freedom to do your install your way.

Its great, isn't it

Many thanks those that used my referral code. Hope you make plenty of money off Axle. https://vpp.axle.energy/landing?ref=R-VYFYIHBL

By constant we have a 6kW inverter and it will provide the house with all power 95+% of the time, which means no expensive imports when battery is supplies the house, is great for exports also. So we can heat the house and cook the tea at the same time if we want.

That's statistics for you, what does mean in numbers a couple or a couple hundred

That would be cash, I would cram as much KWh capacity in you can afford/have space for, then play with tariff import (and PV generation) I'll and export rates, got a 23p export slot coming up which runs for a couple of hours, so good to have plenty of capacity then you can export and run your heat pump also. So no point having a small inverter either.

You don't need anywhere near that much, if that's what being quoted look elsewhere.

System is pretty simple They trigger an export event at you battery/inverter. It then exports battery power plus any other power being generated at that time, as your battery will not charge and discharge at the same time. Axle pay an agreed amount per kWh and your energy supplier will also pay you the agreed export value. Plus if Octopus have an energy saving event, sign on to that, it sees you are exporting and you get a tick in the box, do 2 energy saving event and get weekend power for 1 hr for free. Why procrastinate, sign up, if you don't like it you can stop - you get £25 for signing up anyway. https://vpp.axle.energy/landing?ref=R-VYFYIHBL

Yes

That's only part of it, you still get paid for export by your energy supplier as well. Tonight I get £1 from Axle plus 39.8p from Octopus per kWh. Plus that's only 5 months of the year so far. Good chance winter will yield more money.

Think you would have to go in manually to adjust min SoC, mine just gets pulled at max rate, but if I start at around 100% we are never below 50% at the end of the event as you are limited by inverter size.

Almost exactly the same as us, 1 2hr event and £106.60. Hopefully another £5ish later today.

Great, generally had 3 events a month since May. Seamless especially when managing your battery via Predbat. Have event today. Axle link referral https://vpp.axle.energy/landing?ref=R-VYFYIHBL

Plus those using something like a heat geek cylinder, could be spending a couple hours heating via the heat pump. I was finding a reported CoP of 3 to 4 over a few years, but reality is I haven't seen a noticeable change in electric consumption or export amounts since moving to immersion only DHW. So really ASHP is not as efficient as it cracked up to be.

Or just time DHW to coincide with peak PV production, heat to normal temperature via immersion thermostat. Leave heat pump to do heating or cooling and immersion to do DHW or if DHW production not needed export, just export or charge battery - maybe both.

We bought a house once, the builder obviously didn't like to use a tape measure, as the garage was just over a metre longer than it should have been - it was great. Nice sized garage to build a kit car (Dax Rush)

No insulation means walls become cold with limited air movement, cold walls equals damp walls when you have very limited air movement caused by adding some furniture in close proximity to the wall. Adding some insulation leads to less cold walls, less damp, no mould A bigger air gap allows more ventilation, leading to less issues. Or just insulate the external walls, no mould less need for heating win, win. May not be a small task but as maybe doing loads anyway a good addition.

Heat pump cylinder is more expensive, vented or unvented is a design choice doesn't matter how it's heated. Unvented runs the cylinder at approx 3 bar, vented has a tank in the loft to supply the pressure. Depends on size of immersion and size of heat pump and how it's set up. It doesn't, but with a heat pump you are EITHER heating house or cylinder, not both. So if cylinder takes a hour to heat in a 3 hour cheap period you only have 2 hours to heat house.

None, mine came with the install that's all.

You don't need any additional sensors, just run above dew point then zero issues. Dew point depends on house temperature. But generally you can run 14 to 16 degs without issue. You don't need a buffer let alone another one. Run it all single zone. Unless you have a real reason to run multiple zones. Two types of fan coils, one designed for below dew point and others that don't. The ones that don't are cheaper and you can run same temp as UFH flows so have a simple system. Just do direct heating, save money buying a heat pump cylinder and heat on ToU tariff. Then you can run heating and DHW in cheap periods.