markocosic

I don't buy it. The regs allow cheap shite so they all make £1 on 10,000,000 cheap shite fridges instead of making £10 on 10,000,000 decent ones. There is not £500 in hardware cost between the two models. £100 perhaps, but not £500.

Definitely not @SteamyTea - some modulate at a high frequency (like an inverter driven compressor) where others switch at a low frequency (like a fixed speed compressor cycling) Even within the same hob/ring the behaviour can differ. The (IKEA) hob I have have appears to turndown from 100% to say 50%, then modulates from 50% to 0% on some rings; whereas on others it appears to modulate down the whole way. Most noticeable on the little mocha pot when making coffee. The cheap shite plug in sits in the table jobbie on the other hand just switches at a low frequency for anything less than 100%. I would guess something to do with the cost of the power electronics to work at different outputs. Perhaps @Radian would know more?

Header is killing scop. What water treatment and metals/materials for heat exchanger?

It probably doesn't have a differential pressure sensor so will defrost on pre set logic rather than by need. Lack of open system volume sounds likely

@SteamyTea The £10 plugs satisfied the high res curiosity for the A2A and a few other widgets - I have the utility grade meter read every minute along with some other mbus sensors for other purposes. I do still need to pay with a Shelly and the induction hob though. I'm curious to document how that cycles at part loads / compare with other models. (gut feel is cheap hobs funny modulate down at all well)

I know that @SteamyTea But why allow the newly released 250+ kWh/yr units at all whilst it's eminently viable to produce sub 125 kWh/yr units?

Tasmota > MQTT > HomeAssistant on a Pi Took an afternoon to setup. Tuya converting the smart plugs then firmware upgrading them was the tedious part. If you buy pre flashed plugs it'd be an absolute piece of cake. A2A is on a proper utility meter but this didn't give the 10 sec interval data to see things waking up and sitting down again etc.

I can't believe folks even consider keeping shite old fridge freezers. Super easy swap and super easy RoI calc. Then again I can't believe firms are allowed to sell shite new fridge freezers either. Local box box store has these two, side by side, with a calc to show that the nicer one uses >4000 kWh less over its lifetime (>€1000) and is therefore worth the extra. Fine - but the price premium being applied is outrageous and why the heck are they even allowed to sell the shite ones still? https://www.senukai.lt/p/saldytuvas-samsung-bespoke-rb38a7b4eb1-ef-saldiklis-apacioje/h3fs https://www.senukai.lt/p/saldytuvas-samsung-rb38c7b6ab1-ef-saldiklis-apacioje/nite

COP for flow temperatures 35C or below will be over 4 for any reasonable unit. You don't need to MCS heat pumps. You can just slam one in independently and rely on no objections within 4 years to make it defacto permitted. Even fancy ones are well under £5k in the (tiny) size that you'd need. 1000 Vs 4000 kWh/yr. Plus all 4000 kWh on-peak usage moves from silly rate to standard rate. Plus those oil filled radiators die. I wager they're at least 2000 kWh/yr. Night use seems silly high unless that's the direct electric hot water. I've also got a lodger - an IT type with a server that eats 1.2 kWh/day plus a daft desktop PC, and I WFH with many work gadgets running 24/7 plus two fridge freezers (1.2-1.5 kWh per day the pair) and MVHR (0.7 kWh/day) and we just about hit 5 kWh/day (so perhaps 2 overnight rate) with nobody home. Energy monitoring plug time perhaps; to find out what those oil filled rads are really eating?

Day night shift of 1-2 kWh hotel loads is the most that should ever be cost effective

Most of the heat pumps those guys use have curve shift etc built into the heat pump controls. (i.e. you can offset the entire weather comp curve up or down to effect night setback or holiday setback) They also have load comp too mind. TRVs as limit stops is more for bedrooms outside the main zone.

I think you can; not just with combi but also pdhw via boiler etc. Wireless units from the shops do not include Opentherm. Wireless units from the Tado website also include Opentherm. https://www.tado.com/all-en/professional-manuals https://www.tado.com/gb-en/professional-manuals Extension kit on low voltage is the one you're after. Not advertised. They got burned enough by less than professional professionals to make a special noddy kit for the UK market.

Yep. Tado deserve a kicking for doing it the way that they did. The market was researched* though. That was the problem. They went out to those buying in meaningful volume - the muppets slapping combis on the wall aka the BG Hive market - and concluded that dumbing down the product was what the UK mass market indeed wanted. If you do buy one that has the functionality in it though (i.e. the wired one) it'll do X-plan / PDHW and their internet skills are are way ahead of Honeywell. As is in they're reliable and the app isn't a dog and the TRVs don't sound like hornets gnashing through a pair of AAs every year etc. *Comments from Tado themselves: The wired thermostat is compatible with Opentherm and many other digital buses (when wired to the boiler), and has been for many years. The 'old' Extension Kit we used to sell is compatible with Opentherm and many other digital buses. The 'new' (2019?) Wireless Receiver (the replacement of the Extension Kit) has 2 versions: EU version. Compatible with Opentherm and many other digital buses. Has 1 relay for legacy boilers. UK version. Has 2 relays for typical UK heating systems (1 heating, 1 hot water). Not compatible with Opentherm or any digital bus. Introducing 2 versions of the Wireless Receiver has obviously been extra work and effort from out perspective. We did this after a strong demand from the UK market for a simple to install, simple to configure device. UK installers were struggling with the configuration and wiring options our then-current devices offered. Because we noticed the adoption of Opentherm with the then-current Extension Kit in the UK was close to zero, we removed it to achieve extra simplicity for installation/wiring/configuration. On the other hand, within the EU roughly no one is using 2 relays and bus adoption is high. Hence the other Wireless Receiver on those markets. To not confuse customers, we simply offer 1 Wireless Receiver per market. We will keep monitoring the demands of the market though. Also with x-to-water Heat Pumps which, depending on the market, tend to be controlled by a digital bus like Opentherm as well. ...what we did in the past in the UK. We had the Extension Kit with 2 relays and bus support. This strategy did not work, many installers in the UK simply could not handle the wiring and configuration options our Extension Kit provided. They ignored our manual, 'knew better', botched the installation and left. Resulting in frustrated customers with no heating. So we changed strategy, and the feedback has become much more positive. To be fair, we do get negative feedback for not offering bus in the UK any more. However, the general gist of the feedback we get from the UK is much more positive nowadays. Back to my words: Therefore both are now on offer; but you can only get the non-muppet version if you're literate enough to order from the Tado website. Having to work with some of the folks that shouldn't be offered the complicated version on a day to day basis; I can appreciate why Tado might do that... Try both. I preferred the Tado setup to a Honeywell setup back when we were comparing both side by side.

It's back by popular demand 😉 The versions targeting f*ckmuppets sold in Screwfix don't have it - to avoid the complaints they got about lukewarm radiators. Buy direct from the tado store and opentherm will be there. No experience with Worcester Bosch.

Connectivity up and down like a whores drawers - Honeywell can't do internet enabled stuff reliably eTRVs eat batteries and are noisy as heck compared with others such as Danfoss Open window detection naff and triggered if you since rooms and open/close doors for example Did I also mention connectivity being crap?Couldn't trust it to do what is there for. Buy Danfoss or Tado if wanting something in this space.

Neat! Fine for boilers as fast as I can see; if you don't need the full possible stored volume of the cylinder. Won't give decent cop on a heat pump when you eventually swap mind.

Trend air fed mask / powered respirator with ear defenders £189.99 inc VAT on Amazon at the moment: https://www.amazon.co.uk/Trend-D2-AIR-PRO-Airshield/dp/B096M7LSM9/

50W per m2 on standby; 100W when powered up; 200W when working hard. Average male.of the order 1.5-2m2 A small plug in radiator is about right. SWMBO says when I'm away the towel rail is needed to maintain the same indoor temperature. At least that's how she claims it's maintained...

HWTHKE around these parts (he who thinks he knows everything)

That's not high. Denmark etc have had 50 cent resi electricity (energy taxes) for years. It's worth every penny of 50p.

Not all. We hold prices but push lead times / availability out when times are busy. Our client base (utility companies in the main) value that consistency though. The majority of construction buyers on the other hand wouldn't think twice trying to beat you down on price this year even if did them a massive favour last year.

Those inputs are largely the same whether working for somebody else or yourself though? (dominated by consumables unless you're a trade that actually requires a van - most of the sparks and plumbers that I know run around in personal unmarked cars and arrange for lumpy stuff to be delivered straight to site) £1000 boiler costs £1000 of personal income for which you'd need to earn £2000 in company income. Therefore to pay somebody else.to do this they'd need to ask £2000 for time that is to them or to you worth only £1000 if you earned it by working for others?

You and me too. Blame the tax system for screwing up your perspective on make vs buy / DIY vs pay. When working for others "the cost is the cost" and you make rational decisions to buy kits, prebuilt assemblies etc. When the government takes a fat wedge* you end up making what would otherwise be irrational decisions because your time to yourself is effectively only worth 1/2 of what it is to somebody else. Congrats on having the ticket! If you're literate you're going to be run ragged indefinitely I suspect. Heat pumps next though? Loads of gas fitters out there. Few competent heat pump folks. Even I'm tempted to start fitting the things. Or would be if it weren't for all the MCS paperwork needed to chase grants in the current climate. Once they quit subsidising them and the paperwork overhead disappears the installs will start getting fun/cost effective/profitable all at the same time... *20% in VAT and 30% for basic up to to the best part of 50% in income taxes past £50k (straight income and employer/employee ni or income/ni/corp tax/divi tax - it's all much the same)

I have a single "3.5 kW" Panasonic Etherea unit downstairs in an averagely crap house. (70 m2 1970s council terrace with "filled" cavity, double glazing, and an awful attic conversion) https://www.saturnsales.co.uk/Panasonic-Etherea-CS-Z35XKEW-Wall-Mounted-System.html It's a little undercharged as it has 15 m of pipework rather than the 7.5 m precharge. Turned it on for the first time on Wednesday. It's set to "17C" which translates to the open plan downstairs at 20C - go figure - and bedrooms upstairs at about 17C. It's set to run from 06:00 to 22:00. The overshoot on Saturday was me cooking. It cycles a lot at this low output. It uses about 4 kWh/day. That feels eminently reasonable for 2C overnight / 10C daytime. The COP ought to be of the order 5 (at 2C) to 8 (at 12C) at low outputs - hence running it during the daytime - but there's no way to check. The "heating biased" CU-VZ12SKE / CS-VZ12SKE unit would be a much better choice. (look at the power numbers for what's nominally the same capacity unit) https://www.aircon.panasonic.eu/MT_en/model/kit-vz12-ske-cs-vz12ske-cu-vz12ske/ The "heat charge" is just for defrost; to avoid cooling the indoor air to defrost the coils.

I'm aware - however if you stuff up the design it's possible to do not much better than an immersion. There should be no need for such spaghetti - it's probably worth a design/control review as well as a workmanship review if performance matters to you.