Gill

@IanMcP There's some cheaper options out there and when I looked at hire cost it was going to be about £70 a day. Resale value on Ebay is pretty good to recoup some cost if you don't plan on hanging onto it. I went with hikmicro pocketE that I picked up new for £230. I asked for recommendation on this thread

I'm looking for independent advice on CWI suitability. When our underfloor insulation was put in, the installer had a look at cavities with a scope, took some photos, though it looked clear and rubble free and recommend we get someone out to do a proper assessment. A company we'd had a few recommends from came, drilled a couple of holes and could not determine if we had cavity walls. They then sent a quote to carry out CWI 🙄 Time to revisit this. I'm not sure about suitability for our place. Quite exposed bungalow west coast Scotland, brickwork isn't rendered, no mains drainage. Any advise on what service I'm looking for? Damp surveyor or is this some specialist survey. I'm drawing a blank on this. Thanks

Plumbworld for most of our bathroom /kitchenette granny flat items. I had one issue with a missing part from the wc and their customer service was spot on. Quick phone call to a person, apology for issue and replacement sent over in two days. Not getting messed around for weeks if things go wrong was refreshing.

I did some very very rough calcs recently more to decide if I should even entertain the idea of batteries. All In one givenergy. Around 5k ex vat. 13.5 kW. Install unknown especially with the new vat drop. 0.17 pence difference between by peak /off peak. Assume I can for at least one third of the year (winter) get 12 kW cheap rate daily from battery. 0.17×12×(365÷3) =248.2 Not great value there over 10 years (assuming performance isn't impacted). Looking at time of use tarrifs with two shorter off peaks I think I can potentially double by charge and discharge twice in a day so closer to 500 a year. If I add solar into the equation then our summer use would all be solar or off peak. Probably a small saving of about £1 a day. I do need to spreadsheet something but the above was enough for me not to bin the thought.

I looked at this the other day. This should be the link to it https://www.fogstar.co.uk/products/fogstar-energy-15-5kwh-48v-battery?variant=41546193174587 Would need inverter and as @MikeGrahamT21 mentions the max output is pretty low. Would love to think battery prices are going to become more competitive as we're now at a point where I think I can at very worst break even and something like givenergy all in one would give us small backup power as an added bonus. Will be interested to see if any vat savings ends up added to install costs.

Interesting. Hadn't heard of these folks but that's a very appealing price. Something else for me to research.

Meant to add.... I'm in Glasgow so Scottish regs.

Converted my garage to granny flat last year. Builder and architect told me I only needed warrant as I was putting water supply in there (already had electric) and changing to habitable space. If we'd not bothered with shower room and just floored and lined, no warrant needed.

Think this is the most useful page I've found for giving details of all tarrifs for your postcode. https://octopus.energy/tariffs/ Took me a while to find it. They could improve the website with some very simple changes. Make it obvious you can't switch to their more complex tarrifs until you join but at least give an option to see them on initial quote.

I got the same result and then searched the go tarrif price for my area. If I understand correctly I would have to switch to their eco 7 and then switch again to the go tarrif. I wonder how much difference that hour makes... Its generally 5.30 -7 am I use if I want the house warmed up in the morning. I'll experiment with 4-5.30am when I'm back to work.

Thanks. Hasn't seen that tarrif. Cheaper than my eco 7 day and night rates and only loses an hour of off peak.

6 for water on cheap rate. Max 3 if we're doing a big cooking session. Summer the eco7 is always better value. Surprised it's still working out cheaper now but we've not had a long very cold spell.

Was mildly surprised fixed rate isn't actually cheaper. Maybe a cold Jan /Feb will mix it up again but for now I'll stick with the E7 and keep checking the maths. Looked into those ecocent type systems a while back and just too expensive with no plumber up my way having the slightest idea about them. I suspect any repair costs could add up. Probably go solar and UVC when I can motivate myself to get into 2024 refurb action.

Around 6 daily for the water. In the summer that's our biggest use and only ever heated on E7.

The maths so far. Tight margins. Still seem to be better on E7 unless I'm messed up my maths. End of August to 31 Dec 1855 day x 0.32797 £608.38 1078 night x 0.1622£ 174.85 Total £783.23 2933 x 0.2816 (Octopus standard) £825.93

If we're going to be home early in the day I'll warm up rooms on e7. If say for example today, I'm out all morning and the temperature isn't too low then no point as the heat will have gone by time time I'm back. If temps are very low then the heating will run all all night to avoid the house base temp getting very low. I also heat the granny flat on e7 when I know ill be working in there so minimal day time top up. This winter is very much experimental to see what works and what doesn't. Edit - also left one storage heater wired up in case I'd undersized the A2A system as fail safe. Haven't used it as yet but was another reason I didn't switch off e7 just yet. That's the maths I need to do. I'm sure at the moment we're better on flat rate. Summer we'd be better on e7 for dhw as we don't run heating or cooling. Put a battery in the mix and time of use tarrif would probably work very well for us year round. I've heard suppliers are unlikely to switch you back to e7 if you move away from it but not sure if that's still accurate.

I think my volumes are right. We do have really quite hight ceilings for a bungalow. It's not traditional - previously was a substation so our living room has very high ceilings. E7 is still getting used for DHW, dishwasher, washing machine. Prior to holidays I'd use to warm living area before I'm up and out for work. With the holidays, that's switched off as I'm not up at 6. I'm quite liking a consistent temp for sleeping so one is sometimes kept on low if the temps have really dipped. I was interested again in batteries now (Feb 2024) the vat saving is not tied to solar instal. Our long term solar plan needs the 'to reroof or not' question answered so all went on hold this year. I need to do some more maths but last I was looking at a givenergy AIO, the ROI was getting where I need it to be. Think that was based on switching to a tarrif that would allow me to fully charge and discharge battery twice daily in winter (if such a tarrif exists) so potentially away from eco 7. The battery wouldn't be a money saver so much as added convenience especially when solar comes into the picture. It would also be nice to have some degree of backup in a power out given we have nothing else heating /powering the house. I'm going to keep a close eye. My initial thought was is wasn't worth the investment for 5 months where heating on and average 2.5 days a week but I didn't think about overheating in summer so another thing on the monitor list. The place was stripped back to brick, reroofed and insulated up so it actually benifits from a blast of eco 7 between 5 and 7 to bring temp up and then it's just top up during the day. I could do with a monitor mind you just for my curiosity.

@Crofter put some basic 6 month in thoughts here. Very different use case - I'm looking for winter gains, but might provide some insight. Happy to help if any questions.

Yes, the mild December has definitely been a bonus. More winter months before I can get too optimistic but I'm quietly hopeful. We can now be even more inconsistent with what we heat which doesn't make for great measurements or comparisons. Living room. Room size 105 m3. Heated evenings /weekends /holidays. Till mid Nov heated 2 to 3 days a week when I wasn't working in the office. Usually set about 22. Bedroom. Room Size 40m3. Heated when temps are low only. It benifits from the living room unit as we're open ish plan. It helps avoid the living room unit working too hard when it's very cold. Set around 18. Bedroom 2. Office room / spare bedroom. Room Size 36m3. Heated when used as office by OH (3 days a week). Overnight +dehumidifier for winter laundry. Or guest staying and no longer being baked overnight. SunRoom. Room size 68m3. Winter only if we're having big family / friend gathering. Twice only this winter so far. Last year just once on Xmas day. Hall & kitchen only gets heated if very cold and then we leave bed 2 door open and run that unit at around 19. Bathrooms we don't heat. Rarely use one off hall and our main absorbs heat from bedroom or living room Unit placement was adjusted a little from pic. Sun room unit is centre of wall and bed 2 unit went on outside outdoor unit wall. Working well for our current layout. Last winter the living room, main bathroom storage heaters were always on at some level after November. Bed 2 only when OH was working at home. Kitchen and hall consistently baltic. 🥶

Thought I'd come back with how the A2A journey has been going so far. We fitted 2 x 2.5 kw and 2 x 3.5 kw indoor units with 2 outdoor in our bungalow to replace 5 storage heaters. Aside from a couple of tests of the AC in summer, it wasn't until September they saw much action. We haven't changed energy tarrif so still eco 7. I'd love to have some like for like stats on energy usage but there are quite a few moving factors. - Old draughty double glazed widows replaced with triple glazed early this year - Underfloor insulation in the suspended floor void - Standalone garage converted into a granny flat with building work starting in July and finishing in November. Build work put a bit of an increase in our daytime electricity and since completion we've had friends stay (10 days total) and I'm heating it on the two or three days a week I'm not in the office. The granny flat has a single 2kW panel heater. - Last year was our first year in the place and we were baltic for much of October /November until we gave up with wearing 12 layers and accepted we needed to top up heat with peak heat when the storage heaters were no longer keeping the temperature above 16. After that, we decided to try to accept the cost, be comfortable (no more than 3 jumpers) and get baseline of what our energy needs really were. I thought I'd share the stats I have. September, October we're down on usage and cost which was a bit of a surprise given building work. I put that down to running heating only for an hour or so when needed and probably a good COP as the temps hadn't dipped way down. November we were up on usage and cost. Not surprising as I was running heating and dehumidifier in the granny flat to draw out last of the moisture, we had a cold snap that coinsided with friends staying in there for a few days. As I mentioned, last year we were trying to avoid top up peak heat which we gave up on as it was making us miserable. December is looking really positive. We've had family round for Xmas day as per 2022 so whole house and sunroom set to sauna ++ to keep the oldies from feeling a chill. This year it was much easier to heat the place and much warmer than last year. One other event that meant whole house and sunroom heating was cranked up again. We've also had young ones in the granny flat this week who are unfamiliar with short showers and off switches. I think we're likely to be £450 this month vs £670 December 2022. (Admittedly Dec last year have a good week + of very low temps where we were going through 80kWh daily). I'm not entirely trusting of the SP app but supposedly it is comparing last year to this year using current prices. If our December saving is comparable to Jan and Feb then hopefully we'll be saving around 500 over those months alone and enjoying more responsive and comfortable heating. Worth noting for balance - ROI not taken into account. Come July potential saving should be clearer (unless we fast track on our solar plans) . New system was about 9k fitted. It will have annual maintenance overhead unlike the storage heaters. System lifespan isn't going to be anything like that of storage heaters. Defrost cycles in very cold weather are regular (quite short periods so far even at - 6). Pure luck that the indoor units we tend to run together when very cold are connected different outdoor units. We opted for high wall mounted units so there's still the cool air pocket down low issue. I do wonder if a ceiling fan might help. It's a different type of heat which takes a bit of getting used to. As the room comes to temp, there's the feeling of cold draft as the air circulates. I find that's avoided if I don't try to crank the heat up very quickly but instead set a timer to give it 1 hour to come up to desired temp. All in ALL, very happy we made the switch and wondering if I'll regret not putting it into the granny flat. Much appreciated all the BH help and advice that went into my lengthy decision making 😁

I went multi split. 2 outdoor controlling 4 indoor (one sunroom, one living room, one in each bedroom). Main reason was the west facing side of our bungalow is always cold unless we get a spell of consistently nice weather. Our spare room /office is there and I wanted option to heat this room while other units are potentially cooling which isn't possible with ducted. I didn't dig much more but I'm sure I'd read that far less fine grained control with ducted system so I'm not sure if you can have one room at 17 and another at 22.

A2A convert here. Currently very slowly renovating a bungalow in central belt. I spent an age trying to work out what would be best for space heating and DHW with the help of BH. You might find this thread has some useful information. TLDR : I decided my best option was dump solar to hot water. Heat pump water still not common enough so if it goes wrong it's potentially harder to get someone qualified to fix which likely comes at a cost.

I set on / off schedule for each day using the remote controls. Currently 2 programs in use Monday - Friday to put the heating on early morning and shuts it off before I head to work. This doesn't use the app. If I'm working at home, I just operate with remote control. If I'm in the office, I'll use the app to turn on the heating as I start my commute home as that isn't a fixed time.

I can't control away from home without Internet. Timers I've previously set using the remote continue to work as does normal remote control operation. It's a strangely disjointed system where the remote offers ability to set 4 schedules a day which must be stored on the unit. The app is simply hitting an api at times programmed into the app - if my router is offline (or mitsubishi cloud was down) it won't work.

My mitsubishi A2A system can be managed remotely. The models I went with have built in WiFi. I find the app clunky - setting timers relies on the app having Internet connection when timers are triggered. Handy for turning on when I'm commuting home or checking / changing temps but not for scheduling in my limited experience. Remote controls for each unit - didn't have any need for hardwired control panels . The unit itself does have thermostat and with high wall mounted, it's always reading a few degrees higher than floor level.