S2D2

I spotted it in this video as I'm about to have a Daikin installed myself: You're right that there are extra brackets to sit it in between the feet and the heatpump so it would be a pain if you don't have a flex connection that would accommodate the change. I'd be tempted by the gutter idea, quick and easy and it might just be enough. I really don't understand the design process of the drainage holes, I have a suitable drain nearby for a condensate pipe but there just doesn't appear to be a way to do this with the Daikins, unlike all other manufacturers, even my cheap A2A unit.

Is that a Daikin Altherma? For some reason they use a series of drainage holes compared to other manufacturers who channel it all to one hole: If its not on a gravel soakaway the only real option is the condensate tray, which looks something like this:

The heat geek website has a similar tool, it will also bring up the epc rating and floor area so you can sanity check it has the right epc. Sit down before you read the price though. I've been through the mill on getting an MCS install over the last year and hit all the issues mentioned here, the epc that came with the house and all of our quotes were based off was out on heat demand by about 50%, mostly due to the previous owner having an electric radiator in the conservatory which meant it was flagged as a habitable room. I'd suggest using the heat punk design tool (not shrunk punk, the full heat loss design) because it allows you to have multiple radiator/flow temp profiles for the same property. Do one with absolutely strict MCS air changes/temps etc. and a flow temp of 50, which octopus install to. This is your absolute best case scenario for getting the BUS grant, I found no reasonably priced MCS installer would go below it. This took me a while to accept because for me MCS gives a heat loss of 5.8kW, whereas in reality we sit at around 3.5-4kW based on gas usage data. Our MCS surveys varied between 6.2-6.8kW, down to 5.8kW after going through the detail with one surveyor. They will accept photographic proof of any fabric improvements. You can then copy the MCS profile with more realistic ACH/temps and see how low you can get the flow temp. Second time round with Octopus they agreed to oversize the radiators (don't ask to reduce the flow temp, they won't) by around 50% which means the system will actually run at 42C flow temp no issues. I've accepted an 8kW Daikin R32 unit after ruling it out a year ago. It's the 4-8kW unit so apparently able to modulate well down to about 300W electrical input. I would not accept the 9kW unit. I did have a promising quote with eon for the arotherm plus 7kW but they were obsessed with adding in second radiators and in the end £3k more expensive than Octopus, so 10-20% efficiency difference is irrelevant at that point. I was fixed on the Vaillant 5kW but the final nail in that coffin is they removed the 250L tank from the compatibility table, so the combination is no longer possible under MCS.

This may be useful, figures are outdated but the methodology would be the same.

I paid £2k extra for a 3kWh battery MCS install at the same time as solar. It was the only battery option with less than a 10 year payback at the time. I have a thread on sizing it based on smart meter data that may be useful. Since they added the third cheap cosy period that tariff has been the winner with 5 hours overnight to charge the EV and never more than 6 hours between cheap periods which works pretty perfectly with the 3kWh battery.

Okay, I lied, Cex will give you a quid for the cpu: https://uk.webuy.com/product-detail?id=SCPUINTI54460A

10 year old tech, nothing unfortunately.

EDF came back £1800 more than my Octopus quote, though my property seems to be a random number generator due to errors on the EPC.

Indeed, the highest is more than twice that of the cheapest quote (after BUS, not a new build). Finally seeing some competition to weed out the made up "we're busy anyway" quotes.

From my limited experience prices are starting to come down, but only really for smaller houses. Octopus fixed quote is now coming back £1.7k cheaper than last year and Eon are just getting in to the game, their provisional quote is £1k cheaper than octopus, but they don't lock it in the same way so that is subject to change before I get the final quote. Get some more quotes, the spread on mine was £4000.

Quasar 2 has been "coming soon" for years. The batteries are perfect for it, the main blocker is the cost of the bidirectional charger due to the lack of demand/competition. Once they come down to hybrid inverter prices it will be viable. DNO view the bidirectional charger the same as any other generating inverter I think.

There's a lot of variables, so YMMV but I've seen thermal clipping of discharge rate and mine is in an integrated garage. The installer groups are full of customers asking why they're importing from the grid when the battery has charge and usually the answer is the battery is too cold. If you have enough headroom in discharge rate then you'll never even notice - you'll probably never notice if the heater is keeping the battery warm either. It's just an inefficiency you can skip if you have space inside, but it's not the end of the world if outside is your only choice.

Don't put it outside, charge/discharge rates will be crippled in cold weather or it'll use a resistance heater to avoid that issue, a waste of the stored energy.

That's the one, the data is the same (daily average temperature) but that website lets you choose where to clip the area (at the "no heating required" point) which in this case represents HDD.

Yes, lower heat loss so the base load of 1kW in the example holds the house at a higher temperature, meaning fewer HDD as they're calculated against the "no heating required" baseline.

100% sink in the middle

Did they specify a flow temp? They proposed ripping out and replacing all my rads to hit a flow temp of 50 and would not allow me to spec larger radiators at my own cost. I raised it with the heat pump team and greg@octopus who just referred it back to the heat pump team. They claim that they design for a scop of 3.3 with an "efficient" flow temp of 50 because 3.1 would cost the same to run as a gas boiler. This year the average Octopus tracker scop needed for price parity is around 3.7, so they're openly talking absolute nonsense. Quoted 5.5k after the 7.5k grant, so not even worth accepting then doing the rads myself later. I was on here touting them as a good option before I hit this brick wall with them.

Octopus refused to design rads for a flow temperature below 50°C for me so they're a non-starter for homes that can (and should) go lower. Smaller local MCS outfit has been much more accommodating.

Don't expect the 15p rate to be around for a lot longer, tracker import is down to around 17p.

I don't understand the price of these things, you could pay a human to do it for about four years for that, how long is the warranty?

Yes, Vaillant I think use a MID approved electricity meter but the MID approved heat meters are very expensive so they use cheaper sensors to calculate flow rate and flow/return temp. Generally regarded as accurate enough, some other manufacturers have been shown to be way off.

Arotherm plus? They're known for outperforming the datasheets when installed well. You're a bit above the crowd at https://heatpumpmonitor.org/ but it depends if your plumber was just rounding up and you will be running at a lower flow temp etc.

The upgrades part of the site is for an ASHP Install quote, if you just want information from their articles try https://www.heatgeek.com/category/knowledge/ or their YouTube channel https://youtube.com/@HeatGeek

I could be wrong, but I think this is the same change that has been in place for new signups since December, so if you signed up recently there won't be an extra increase. They're now moving old signups which weren't a fixed term tariff (which the new one is) to the new rates.

Octopus Tracker has had by far the best rates over the last year. Obviously it's not without risk as prices change daily but as long as the market is on a downward trend it should be a winner.