S2D2

Ideally get the humidity below 60% to see if you still have an issue, 70% is too high.

I'm toying with this Vs Cosy for the heat pump/battery over winter. The API is simple and can be integrated with whichever control system you need via your chosen HA setup. Plan would be to charge battery/run heatpump in the n cheapest half hour slots. You need to predict your heat demand as that determines the number of slots you need to run for. Then it's just a case of does that average price make it worthwhile. I haven't modelled it yet to get that answer.

Thanks for the tip, couldn't find one of these at the time of install but swapped out the P trap of a SK1A with this and it's much quieter now.

https://octopus.energy/press/octopus-energy-unveils-next-stage-in-smart-heat-revolution-at-energy-tech-summit/ Not really any more information though.

An extra 208x2x23=9.568kW surely? ACH assumptions make a huge difference to heat loss calculations, particularly in well insulated large houses. @SteamyTea's worked example shows that clearly, 84W for fabric and 208W for 1ACH. As mentioned above, it's the realistic value you want to use not the @50Pa result.

The air changes per hour will make a huge difference and you should be nowhere near 3 in a new build. Try 1 as a conservative starting point.

Until you have visitors, who will inexplicably park on lawns/middle of roads/millimetres from the edge of your retaining wall...

B is the measurement I use for this. Ensure its the same for the socket.

I went with underneath the end panel, looks way better than the alternative.

Is this just a one off to confirm they have the right export meter configured? I can't remember if I did this initially, but all export on flux is handled by smart meter readings now, no manual reads. I have an "upgraded" SMETS1 meter.

@zoothorn I answered this back on page 2, and again on page 3 when you typed it out in all caps. Maybe I should have typed the response in all caps? With the above picture it is clear. The hydraulic module contains the backup heater, so your current system requires a smaller system volume. Ask them why they aren't fitting the backup heater with the new system. It will cost more to run than a buffer, which may be the reason. If they are, ask to see their system volume calculations and post them here. If you repeat again that nobody has answered this question I highly doubt you'll get any more replies.

It depends which ASHP and tariff. I think at the new variable October rates it's around a cop of 3.6 needed to be cheaper, easily achieved by a well installed system and modern ASHP. Any time of use reductions to electricity rate likely to make it a no brainer if that works for them.

I don't know if you've stated elsewhere which model you currently have and which they are replacing it with, but the "old" arotherm has a stated minimum volume of 35l for the 11kW model. It's not clear whether this is with or without the "backup heater" I mentioned previously, but a different minimum system volume spec could explain the inclusion of a buffer if you are moving from an arotherm to an arotherm plus.

If you're wanting the over-complication route, temp sensor on the underside of the bath that overrides the timeout when hot (bath in progress)

Assuming they are replacing with an Arotherm Plus, they have a rather odd step in the minimum system volume dependent on size. 10/12kW models: 150l 7kW: 55l 3.5/5kW: 40l I've only just started looking at this but I doubt anyone is fitting a big enough buffer to hit 150l, so I would query this with them as it seems a massive jump from 55l to 150l. Getting down to a 7kW model might solve the headache if you can make up the system volume in the radiators/pipework. You can also drastically reduce the required volume with the 6kW backup heater which is relatively small but will cost more to run, I have no idea how much it would come on for normal usage, I've only just seen that it exists. Including this changes the minimum volumes to: 10/12kW models: 45l 7kW: 20l 3.5/5kW: 15l Which you should be able to hit with radiators alone. Information for the larger units here in appendix E: https://www.vaillant.co.uk/downloads/product-brochures/arotherm-plus-230v-double-2626669.pdf

I think it might have been a typo, they specify minimum system volume, not minimum buffer size. It can be quite large for the bigger units, hence the use of buffers.

It drives me mad when microwaves make this sort of thing difficult. AEG for reference, though not all black: 1000W, 30 seconds: Hit OK button once. Each press increases time by 30s. User experience gold medal. 800W 20 seconds (can't actually do 15): Hit microwave button 3 times (wake at 1000, 900, 800), hit timer button, hit increase button twice (10s, 20s), hit OK I never use the timer button, just set the power then hammer okay for 30s intervals. Anything less than 30s I just open the door. Timer button is just too many extra taps, especially with the major design fail that tapping the timer button starts you off at 0s. This is useful to nobody, and hilariously turns the microwave off if you click okay at this point in the workflow.

Best to ask your installer referencing the exact tiles, we had no issues with lifting and refitting tiles but they'd just come from a job with a difficult type (I can't remember which sorry) where they'd broken and had to replace a dozen or so getting them off.

I find cheap rigger gloves enough for brambles, YMMV and the ones ~15 times the cost will be better.

As a random sample, MCS cost me maybe £1.5k (vs DIY, less vs non-MCS install) and I've had £400 of export payments over the last six months. I filled the roof as the relative cost was minimal so generate more than I need. The company I used are now charging more, so that may be an exception, but certainly worth it in my case. Flux may disappear overnight as well, they've already reduced export rates in line with import prices which track the price cap.

If the holes are too large this will be a problem, they need to be small enough to not cause a significant pressure drop which would affect the flow rate of everything downstream.

As I've said elsewhere, the key battery feature for me is shifting daytime export that would otherwise get 15p to the peak export window at ~30p (new rates). The key feature overall is the higher export rate. The symmetry in rates means you can charge the battery in the cheap window without thinking about it, but nothing says that you have to. Any import is offset by later export, though as I said over in the other thread Octopus just narrowed the inefficiency allowance in their latest price update: Hybrid inverters always prioritise PV for self-use before pulling from the battery, yes. Even if prioritising feed-in or force discharging, the house still uses the energy first before export takes place. My average export unit rate on flux since March has been a little over 25p. As it is a complex tariff, I agree that it needs careful thought before use.

I prefer a platform for above the stairs, like this but without the top steps if you don't need the extra height: Much more comfortable than being up a ladder.

That's annoying for anyone hoping to get one in for winter, but I guess demand for air con will be high at the moment. I've had it on a couple of times for this in the recent heatwave and it's great at getting the heat out of downstairs, where I have the unit fitted. Not much gets to upstairs because it's positioned for heating and I haven't been running it for very long. It uses more power to cool, around 600W compared to 400W for heating but again not sure if that's because I haven't run it for long.

Some interesting pricing changes to Flux from July: Import fees are reducing by ~8% for all three time periods Export has different changes for each though: Peak reducing by ~11% Overnight reducing by ~20% (not that you would be exporting during this) Day reducing by ~13% That changes the maths a little to make this tariff not quite symmetric: Old overnight import vs day export allowed ~8.5% efficiency losses to be symmetric, new is ~4% Old day import vs peak export allowed ~5% efficiency losses to be symmetric, new is ~2.5% This makes peak export trickier, there will be some inefficiencies for a full discharge followed by buying from the grid until 2am, but still an incentive to not have charge left in the battery by 2am that you could have exported during the peak window. Altogether not a game changer, still a very good tariff.