Solar settings explained
What each solar setting does and how it affects your hot water.
If your home has solar panels, a compatible Mixergy setup can use electricity that your home is generating but not using elsewhere. This is called spare solar electricity. Using it to heat water can help you make better use of the energy your panels produce.
The installer normally sets up the solar controls. The standard settings suit most homes, so only change them if you understand what they do or have been advised to do so.
Where can I find the solar settings?
Open the Mixergy app and select your tank. Open the menu at the top right, choose Tank Settings and look for PV Diverter Settings or PV Diverter Schedule. PV refers to solar panels that generate electricity.
These controls apply to supported Mixergy solar equipment. If another manufacturer’s diverter supplies the tank, its own controls manage solar diversion.
The options you see depend on the Mixergy product, solar equipment and access provided for your home. Some settings will not appear on every system.
Use spare PV to heat tank
Switch this on if you want the tank to use available spare solar electricity. If it is off, spare solar will not be used through the Mixergy solar controls.
A solar schedule can limit the times when spare electricity is used. Without a schedule, the system can use it whenever it is available and the tank can accept more heat.
PV charge limit
This is a limit on the amount of hot water solar heating can prepare, not a temperature setting. You might see it labelled PV Charge Limit or PV Chart Limit.
For example, 50% allows solar heating up to about half the tank’s usable hot water capacity. A limit of 100% allows spare solar to heat the full usable amount. These are examples of how the control works.
It does not make the tank heat to 100% every day. The result still depends on the amount of spare solar, the tank’s current level and the other settings.
PV diverter target temperature
This sets the maximum water temperature target for solar heating. It is normally set during installation, often at around 60°C.
If the separate solar target is turned off, the system follows the tank’s usual temperature target. Do not raise either temperature without advice from the installer or housing provider.
Display solar power in Insights
This controls whether supported solar-power information appears in the app; it does not switch solar heating on. To see the information, open Graphs from the tank screen or main menu and choose PV Power.
The reading can change quickly. Clouds reduce solar generation, while kettles, ovens and other appliances use electricity that might otherwise be spare.
Look at several suitable daylight periods. One cloudy day or a short gap in the graph does not show that the solar system has a fault.
What if a setting is missing or locked?
The setting may not apply to your equipment. The app may also be unable to detect the solar controls, or a landlord or housing provider may manage access.
Do not repeatedly change other settings to make the option appear. Ask the installer, landlord or housing provider which solar equipment is fitted and who manages it.
Do not move a CT clamp, open electrical equipment or change solar wiring. A CT clamp is a small sensor fitted around a cable to measure electricity flow. A competent installer must check it.
Can I still use the tank without the app?
Yes. The solar controls can continue to operate. You can check your hot-water level and heat more water using the gauge.
[IMAGE – SOLAR SETTINGS]
Use: App screen showing Use spare PV to heat tank, PV charge limit, solar target temperature and Display solar power in Insights.
Caption: The settings shown depend on the solar equipment fitted.
Alt text: Mixergy app showing the main solar settings.
Common questions
Does solar heat the tank before powering my home?
No. Your home uses the electricity being generated first. Only the spare amount is available to heat water.
Should I set the PV charge limit to 100%?
Leave the installer’s setting in place unless you have a reason to change it. A higher limit permits a larger amount to be heated by solar. It does not create extra cold-water capacity if your normal schedule has already heated the tank.
Why does the app show no solar power?
There may be no spare electricity, the tank may already be at its target, or your setup may not report solar power to the app. Check again during strong daylight before asking the installer to investigate.
Why does the solar reading keep changing?
Solar generation and household electricity use both change throughout the day. This makes the spare amount rise and fall, sometimes within seconds.
Will changing these settings reduce my bill?
Not automatically. They can help the tank use more of your spare solar electricity, but the result depends on the weather, your hot-water use, your tariff and the equipment fitted.