Mixergy Installation Guide - MX Range

If you're an Installer with G3 Certification, this video will take you through the complete installation requirements for a Mixergy smart hot water cylinder.
Use the chapter markers to navigate through:
00:30 - Introduction
01:01 - Installation Considerations
02:41 - Main Wiring
03:11 - Primary Supply Cable
03:33 - Indirect Control Cable
04:16 - Timer Control Cable
04:42 - Heat Pump Options
06:07 - Solar PV
07:21 - Mixergy PV Switch, 3rd Party Diverter
If you have any questions, don't hesitate to get in touch with our technical team: www.mixergy.co.uk/contact

[@Smart_fix]

Great information well done 👍🏼

[@mixergyltd6286]

Thanks!

[@jeffjsmith]

Great to see this video - really clear and useful. The question I would have is whether your advice on using PV power with the tank is valid when you have a heat pump, especially in the summer. We heat our 210 litre tank from about 20% to 75% daily, with the top of the tank reaching 44 degrees (and the heat pump running to about 50 degrees maximum flow temperature). The daily heating in the summer typically uses about 0.7 kWh of electricity - very efficient. I am certain that the immersion heater in the Mixergy would consume significantly more energy for the same water heating. We do get 11p / kWh from Octopus from our export, so the 'cost' to us of heating the tank is about 8p. If the Mixergy used 2 kWh of energy to heat the tank to the same level (my guess) it would cost us 2 * 11 = 22p in lost export. When we change tariff at the end of the year, the export rate will be rising to 19p / kWh, and so the cost would be more. We will be buying another Mixergy for our other property, and this will also have solar panels and a heat pump. I will be getting the embedded PV diverter, but I am not sure that I will ever use it. Any thoughts? (P.S. We do have a Tesla Powerwall at both properties).

[@mixergyltd6286]

Ideally, with a heat pump, heating the tank to 100% gets the most out of the Mixergy and the heat pump. With Mixergy using PV to heat the tank, the idea is that the house and all other devices (including batteries) are satisfied first, and then the excess can be used for heating your water (Mixergy). In theory, the immersion does use more electricity to heat up, but when using the immersion on PV you can set specific percentages and specific temperatures and also, it does not use power from the Grid, it is free generated power. This means during the summer, you could heat only 30% of the tank for free rather than the higher charge percentages required when using a Heat Pump and sell the excess if required. If the property has a lot of reliance on electricity, i.e. Batteries, EV chargers, large appliances like hot tubs, pools, electric storage heaters etc. then it may be that there is very rarely any excess solar power available to heat the Mixergy. And then, you must consider the size of the Solar array. It's all about finding the balance that suits each property, everyone has different requirements.

[@jeffjsmith]

@@mixergyltd6286 Thanks very much for the detailed reply. I think you make good points, and we feel that the flexibility that the Mixergy gives in terms of heat source and controls means that it will cope with the different changes in energy price levels and individual requirements, and the changing needs during the year, mean that Mixergy is just perfect. At the moment we might not use our PV diverter but who knows next year?