S2D2

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.

In hindsight, Cosy worked well but ended up costing £30 more than just being on Octopus Tracker for 3 months, before even factoring in battery inefficiencies. So I'm just on Tracker now. Obviously tracker won't stay cheaper forever, but at present with low rates on Tracker there just isn't a use case for Cosy to me. It still compares well against standard variable, of course. Flux was a different beast, over £200 better being on that over summer compared to Tracker with fixed export at 15p, so I'll switch back to that again in the spring depending on where export rates go.

Zero and 3 will behave the same (full OS with Python on top). CircuitPython is for things like the Pico. Good luck.

adafruit_mlx90614 is the CircuitPython library (https://docs.circuitpython.org/projects/mlx90614/en/latest/api.html) so you'd have to flash the firmware to your microcontroller. I'm assuming instead you're using a zero or such with a standard python install, so you'd want another library. The one you linked might work but note the different name for pip/include: https://pypi.org/project/PyMLX90614/ Full disclaimer I've never used any of this stuff so could be completely wrong.

Adtran box will be the ONT probably, Linksys modem+router. It should have spare ethernet ports in the back, if so you don't need a switch?

Tracker is a daily price. Agile has half-hourly pricing that varies over the day. Both have their rates set the day before or so.

https://energy-stats.uk/ Choose tracker and your region from the menu.

What really blew my mind was Octopus were proposing changing all the rads anyway to hit 50°C. The incremental cost to hit 45 or 40 would have been very small and would have been totally appropriate for my house. Whatever happened to consumers paying for what they wanted? It went all the way to the head of their heat pump operation and it was a flat out "No, we won't design below 50°C". Just change one text box, have the automated number crunching done and install what has been asked for provided it's within the realms of sensible, I don't see the issue.

Not sure, I'll let you know when I get round to it.

https://protonsforbreakfast.wordpress.com/2023/04/02/another-heat-pump-spreadsheet-beyond-the-rule-of-thumb/

Somewhat unbelievably, Octopus will not install rads larger than those for a design flow temp of 50°C. So this is definitely the way they're going.

Yes, unless the heat loss calculation is not accurate. Which yes, it might not be, even with an MCS registered installer.

This too, but you can get a heat pump quote through them which they will "guarantee" by providing the MCS component to a heat geek trained installer who is not MCS registered. It's a more recent initiative than their training/accreditation business. To complicate things, some heat geek trained installers are also MCS registered, so you can go directly to them instead but you are not covered by the heat geek SCoP guarantee.

In the radiator schedule which is included in the MCS quote along with the stated SCoP. I do agree with everything else, companies are free to register with MCS then break the rules. The umbrella companies are less risky in this regard, they would prefer to fix one bodged install than lose their entire business model by having MCS registration revoked. But yes, that shouldn't be the only tool consumers have when things go wrong, especially with the amounts of money involved.

It is, because that SCoP is tied to the rest of the design. It also directly affects the cost of running. I don't have a solution to installers being crap, but there's nothing to stop a heat pump working perfectly well if it is designed and installed properly. The up front cost is the pain point, hence the efforts to make them run like gas boilers at high temps. You save a few thousand on install costs but a poor SCoP increases your running costs. No different to any other cost/performance trade off.

Heat Geek are an umbrella MCS company which cover hundreds of installers. The MCS calcs have a design temp which will be stated on your radiator schedule. The SCoP stated is for that internal temperature as it's all linked to radiator sizes and flow temperatures. The main issue is the calcs not being done correctly. That's something that should be enforceable by MCS to fix but yeah right. Care is needed but it's not difficult to make all of these things line up.