Mixergy hot water tank

AntonyTewks

Just wondering if anyone has experience of these and what that experience has been. I'm planning to get soon as part of our drive to decarbonise/electrify and have had a few quotes back. We currently have a gas heated tank that's 20+ years old and not the best insulated. Aim is to get this with an electric element so no longer need gas for hot water. To try to get the running costs as close as possible to gas it should only heat what we need/use, we can link it to our solar hot water diverter in the summer and it also works with Octopus agile so should only heat during the cheapest periods. Aware it's a very new company though, seems to have some big backing. I rather like the data and the app that comes with it too.

tacpot12

I wasn't aware of Mixergy before your post, but I've had a look at their website, and at their investors. I think that the concept makes a lot of sense. The tank seem well thought out; high-efficiency components have been selected throughout the design, the tank is laid out to make it easy to install, and all the installation options have been catered for. I was pleased to see a hard-wired connection to the home network was possible. The clever bit is in the AI that optimizes the use of energy. I think this company will do well, providing their tanks prove to be reliable. As they are build in stainless steel, I expect they will be.  

Martyn1981

Hi, if it helps, the name rang a bell and I remember Fully Charged doing an episode on it, though I can't remember much more than that.

Mixergy - Fully Charged

AntonyTewks

Yes that's where I first spotted it, not seen too much of it in the wild yet. I know it was included in a research project and been put in some new builds

AntonyTewks

Just to update that I finally had it installed and some feedback if useful for anyone. I'm quite impressed. You're always getting hot water through, even when only 10% of the tank left you get that 10% undiluted and nice and hot. It works much better with my solar. Before only a small amount would be diverted, I think as the immersion was top of the tank the thermostat was cutting out pretty quick. Now it's slurps up the excess and even in winter on half decent days it's adding15% or so. Finally I've found that we only use about 70% of the tank at the most. Before we would heat our whole tank with gas using maybe 12-14kwh gas across the day. I think I'm now using around half that amount in electricity, perhaps 6--7kwh, heating 50-70% of the tank which is helping to bring the costs closer despite electric unit costs being a bit higher (being on agile helps)

AntonyTewks

some of the stuff you get on the app

I'm just waiting on the agile integration now

Solarchaser

Hi Antony that's great info thanks.
I like some of the mixergy stuff, the moving of the stratification layer is a great idea, but I also like the idea of a thermal store.... not least as the actual water is heated indirectly by the tank (dirty) water.

The ideal would probably be a mixergy controlled thermal store.

Can you tell us what size of cylinder you got, how many users are there in your household.... and how much it all cost?

AntonyTewks

I looked at the likes of Sunamp but it was a fair bit more expensive from recollection though a much more compact package. The mixergy wasn't cheap. We had a 140l tank before and got the 150l tank. Mixergy gives guidance on the site around size and that was what was suggested for us - 2 adults and 2 kids.  It comes to close to £2k including labour. When I had a seperate quote for the tank that was about £1.2k including the dual immersion for the PV diverter . Labour was fairly high because they changed us to an unvented system for better pressure. 

Solarchaser

Oh, interesting,  I was thinking with a house of 6 the 210 would be no-where near enough.

Thanks for the info 👍

michaels

We are a family of 5 and have a 250l tank at 60 degrees and still need to have the boiler top up the water each morning and evening as we use more than that.

Solarchaser

I was thinking a 500l tank would be about right for me, but I'm not sure how much of that is driven by my not wanting to export leccy, and so wanting something to sink alot of kwh into in summer