Intelligent Flux with Solar Boost for hot water

Changed to IF about a week ago from Flux. On Flux when battery was 100% I.e. full the boost would heat the hot water cylinder. Since being on IF we have had hot water but couldn't think why as battery has never been above 80%. Have just been in airing cupboard and the Solar Boost is on and heating water with only 62% battery. What's going on?

An explanation would be great! On a different post it was explained that you use the grid like the battery except from 4pm to 7pm but we have no way of communicating to battery that we want the water to be heated so don't know why the Solar Boost has come on.

Lynn so don't know why the Solar Boost has come on.

Perhaps the Solar Boost is configured to automatically detect when there is export, based on the assumption that this would only be when the battery was full. But on IF, it's probably either exporting or importing at all times, not just quietly keeping the grid activity at a minimum as eco mode would normally do.

That would be so good if it was working like that. Battery is defintely still exporting at the moment and at 62%.
Thanks again for another prompt explanation.

We had our iBoost on in the summer and noticed that when we did a timed export in the evening if the water was cold the iBoost would turn on treating it as normal export. Worked quite well saving the last dregs of our oil until the ashp arrived

Lynn That would be so good if it was working like that.

Hmm... possibly not. Octopus are likely to export during the 4-7pm slot, and you'd almost certainly be better to allow that power to go out (so you get paid for it) than to self-consume it.

Perhaps a Solar Boost isn't so useful on IF - there really isn't any incentive to self-consume. I'm in a similar position on Intelligent Go - better to shift consumption overnight from grid, and export whatever solar I produce, rather than consuming it.

Oh that is something I hadn't thought of but maybe still ok as we haven't had the gas on at all for heating or hot water so maybe it will balance out.

I also have a Solar Boost but we're on standard OF not IF and yes, if I do a timed export at peak time it will always dump it into the hot water in the first instance which is very annoying when I want to get paid peak rate for it instead! I have come to the conclusion that if I want the benefit of having the hot water topped up with surplus solar during the day but export in peak period I will have to fit a time switch to the Solar Boost mains input to turn it off during peak time, not so easy with IF though!

I have an Eddi, so have stayed away from IOF for this reason. In the summer, on regular Flux, I schedule the Eddi to go into stop mode during the peak rate period when I'm usually doing a forced export, so that I don't end up with a tank of expensive hot water.

I turned my iBoost off once I started getting paid for exports as it's more cost effective to use oil to heat water than lose the export payment.
Since I moved to Agile I've switched it back on to be able to schedule charging from the grid on those rare negative import slots and I have removed the batteries from the iBoost clamp sender to avoid heating during export.

So it does go to hot water first with IF when exporting. Will have to stick with it and see how it costs out. We hadn't been getting much for the export on Flux so will have to wait for a month or so to see if it's worth staying on IF. Our gas bill which had been horrendous is now just standing charge as we haven't used it since getting the solar panels in April.
Thank you everyone.

Lynn Yes it will go to hot water when exporting until the target temp is reached. Depending on the export rate in your region, you're effectively paying around 20–30p/kwh to heat your water, vs 6–7p/kwh for gas. You are at least reducing NOx pollution in your local area!

Avenir
So IF is not a good choice for us? If we went back to Flux and I left settings on eco plus max charge between 2am and 5am then export between 4pm and 7pm would that be any better? We found it difficult to export and then leave enough in battery to cover evening use. (We cook and eat at about 7.30pm.) Electricity would come from grid then. It seemed to need constant vigilance to ensure battery was used at times rather than grid.

Lynn So IF is not a good choice for us? If we went back to Flux and I left settings on eco plus max charge between 2am and 5am then export between 4pm and 7pm would that be any better?

Possibly not if the solar boost is just going to grab any export and divert it.

On a dull day, how do you heat your water - gas or electricity? If the former, just switch the boost off? Or you use electricity using the boost to control the immersion, perhaps remove its CT clamp and operate it as a timer only?

Lynn When I was on Flux in the summer I would stop the Eddi from 4–7pm then export my 9.5kwh battery to 50pct from around 5.30–7pm depending on next day forecast (all automated). This left enough in the battery to see me through until morning; the hot water was heated by excess solar earlier in the day.

Now we are in autumn and don’t have excess solar, I’ve switched to Go. The Eddi is used as a timer to heat the water overnight for something like 8.5p. Taking into account the inefficiency of my ageing system boiler, this is approaching cost parity with gas and means I can run the boiler at 40C for central heating, which saved me quite a bit of money last winter.

DD
We used gas to heat the water but in combination with heating up until April. We then put up with warm/cold water when we had dull days in the summer! We should have checked cost of gas heating up water before changing to IF but didn't realise the effect of IF on the booster.
I don't understand your suggestion of removing the clamp and using the booster as a timer only. I don't know what/where the clamp is and how to use a timer for heating the water. Is that straightforward?
As you are aware we are still total novices of all of this.
Avenir
How do you use Eddi as a timer?
Thankyou both of you. Looking at usage for Monday we appear to have imported a lot but hardly exported any which isn't good. Will have to do something but not sure what. Is it easy switching and then switching again? This was first switch since getting panels and battery.

Just a thought. Can I turn the booster off at the wall as I did when we were on holiday and then turn it back on when we need more hot water? Or is this going to limit the life of it?
Thank you for your suggestions. Much appreciated.

Lynn We used gas to heat the water but in combination with heating up until April. We then put up with warm/cold water when we had dull days in the summer! We should have checked cost of gas heating up water before changing to IF but didn't realise the effect of IF on the booster.

Looks like gas is 6.32p/kWh in our region on SVT. Our electric was Octopus Intelligent Go, which gave us 7.5p/kWh, then 7p/kWh, overnight, so, given inefficiencies of gas boiler, we'd been using overnight electricity to heat water. But if you still have gas, that's almost certainly cheaper than using electricity on IF (at any time).

I don't understand your suggestion of removing the clamp and using the booster as a timer only. I don't know what/where the clamp is and how to use a timer for heating the water. Is that straightforward?

Okay. First off, what's the exact model of your Solar Boost ? I'm aware of a thing called Solar iBoost.
https://www.marlec.co.uk/product/solar-iboost/
In the middle picture in 'How it works', it shows a white box around a cable from the meter - that's the CT clamp, and how it measures import/export. If you simply unclip it, it can't detect any export. (That's assuming there isn't a way to simply configure it not to use solar to heat water.)

That page also says you can configure boosts on a timer.

(Page also contains some text "Thanks to Solar iBoost+, water is heated over the day using just the free solar energy." Which is all very well, but I don't consider my solar to be free - using it means I miss out on selling it for 15p, so that's its worth to me.)

Lynn Just a thought. Can I turn the booster off at the wall as I did when we were on holiday and then turn it back on when we need more hot water? Or is this going to limit the life of it?

Yes. But, unless you have a separate timer switch for your immersion, you'd also lose that feature.

Lynn If you're sticking with IF, I'd suggest just switching it off completely and heating the water with gas.

If you switch to Go, then you can leave it switched on, since the export rate is poor. Take a look at whether it makes sense for you to heat your water overnight using immersion rather than gas – it works for my specific circumstances, but it's not for everyone. I guess there must be a timed boost function somewhere? To use the Eddi as a timer I just schedule a boost in the app. Scheduling Stop Mode requires a third party integration.

I think you have to be on a smart tariff for at least 30 days before you can switch. Probably easiest to call them.

Avenir I thought Go was for those with an EV or have I looked it up incorrectly?

DD
Thank you. Yes that is our booster. Will now look up timing on it but might well turn it off and check what gas costs us to heat the water. This has all been a lesson to double check everything first.
Many thanks.

Lynn It is, but they don't check. Charging your battery and hot water overnight will be similar usage to topping up an EV. Proceed at own risk, etc.

Lynn or there's eon next drive, which has slightly better terms, but is for either EV or solar/battery.

DD Thank you. I haven't looked at other providers as Octopus seems to have better customer service with a good app. I will definitely compare with Eon though.
Thanks again!

DD That's a good shout @DD. At 6.7p for a 7hr off peak, it sounds better than Go. Will be taking a close look at this myself!

Avenir Tomato Energy is another new player which looks good on paper, but support might not be all the way there yet...
https://community.givenergy.cloud/d/5014-winter-strategy/82

DD
I wonder if Octopus will respond to this and open up the " Go " tariff to people with batteries but no vehicle. One can hope 🤞

There's flux and Intel flux so I doubt it...

Turned off Eco boost for water today and set the timer for water with gas for an hour to compare price. New problem as heating came on at same time. Temperature on thermostat in hall was at lowest so heating shouldn't have come on at all. So somewhere we have a fault.

Lynn New problem as heating came on at same time

Possibly a stuck diverter valve? My system had a 3-way valve to direct the water to water, radiators, or both. It would spend the entire summer at the water position, then be reluctant to move once heating was required. If youve not been using gas for water, might be sticking in the radiators position.

On cost comparison, bear in mind that they'll use different thermostats, and heat different volumes, so should measure over a week or so.

Lynn all radiators or just towel rails? Sometimes these are on the hot water circuit.

DD Thank you for this. I think we had this problem a few years ago. I had totally forgotten about that problem. This does seem the most likely problem as all the radiators were hot with with hall thermostat on very low.
Thank you again....that's what husband will try and fix. I think he will have to ask google as we have both forgotten how it was fixed!

Or maybe get a plumber to sort it.
Thanks again!

Lynn There’s usually two parts to the motorised valve. The motor on the top and the actual valve mechanism underneath with the top simply bolted to the bottom part.

Often there’s a lever on the side of the valve you can use to manually operate it, open and close the valve a few times can free it. If it is still not working you can unbolt the motor off the top and rotate the valve by hand/with a small spanner.
If the motor has stopped working then it can be replaced with an identical one without having to drain down the system but if the valve has totally seized then its starting to get towards a plumber job to replace

https://www.youtube.com/watch?v=KT6mq1440zM
https://www.youtube.com/watch?v=hXwXo5SJlC0

Thank you. We will have a go at this as it seems too straightforward. The cost of the water and heating for 1hr 20 mins before we realised the heating was on was £1.09. Hopefully when we get this sorted it will be much less.
Thanks again.

Avenir

That's a good shout @DD. At 6.7p for a 7hr off peak, it sounds better than Go. Will be taking a close look at this myself!

I switched to Eon Next. Thanks for the tip @DD!

It took 3 days to switch to their standard tariff, then 5 more days to get onto the Next Drive v4 tariff. All fairly smooth so far and customer service folks have been helpful.

Switching the export over is taking a bit longer because it requires a schematic. I have sent them the relevant one of these, after getting confirmation from my installer: https://midsummerwholesale.co.uk/pdfs/givenergy-full-schematics.pdf

Lynn Hopefully when we get this sorted it will be much less.

Any news ?

Avenir Switching the export over is taking a bit longer because it requires a schematic.

Oerr... they're not like Scottish Power are they, where they will only pay for energy you've generated, rather than "brown" energy which has come from the battery ? (So that the schematic has to somehow show that the battery output doesn't get measured by the meter, which I still don't understand.)

Obligation 3.1.(h) at https://web-content.scottishpower.co.uk/files/pdf/seg/smart-export-guarantee-tcs-nov-2022.pdf

DD No, as far as I can tell there is no such restriction. Will see what they say!

DD
Thank you! Had valve sorted. Heating now ok
And water sorted too. Have tried gas on for just over an hour to heat water. Turned all ecoboost and immersion switches off. Came to just under 50p so can live with that.
Have new problem with internet but will post new question.
Thanks everyone.