Heat Geek Mode

Heat Geek Mode is an advanced option for a Mixergy tank heated by a heat pump. It allows different temperature settings, with the aim of making hot water heating more efficient.

A heat pump transfers warmth into the water in your tank. It generally works more efficiently when it does not have to heat water to such a high temperature. Heat Geek Mode allows lower temperatures, but the settings also affect how much hot water is counted as ready to use.

You do not need this mode to use a heat pump with your Mixergy tank. Most residents should keep the normal settings unless their installer has set up Heat Geek Mode for their system.

Is it suitable for my tank?

Heat Geek Mode is only available when Heat Pump is selected as the tank’s heat source. The heat source tells the tank which equipment will heat its water.

Do not change that selection just to make Heat Geek Mode appear. Ask the installer responsible for your system whether the mode is suitable. If you rent, speak to your landlord or housing provider before changing it.

What does it change?

Heat Geek Mode allows the system to:

• Use a tank temperature below 50°C.
• Adjust the temperature threshold used to count water as ready to use.
• Reduce unnecessary repeated heating cycles when configured appropriately.
• Use time-of-use tariff information when optimising heating. This is an electricity tariff with prices that vary at different times.

These changes need to work together. A lower temperature is not automatically the best setting for every household, and lower bills are not guaranteed.

What does “minimum output temperature” mean?

The app’s hot-water percentage is an estimate of how much water is hot enough to use. Minimum output temperature is the lower temperature limit used in that calculation.

In plain English, it tells the tank how warm water needs to be before it counts towards your available hot water level. It is different from the target temperature, which is the temperature the tank aims to heat the water to.

If the minimum output temperature is very close to the target, even a small amount of cooling can make water fall below that limit. The displayed hot-water percentage can then drop quickly, even though the water has only cooled a little.

The default minimum output temperature is 43°C. The available adjustment range is 15°C to 50°C. That range describes the control’s limits; it is not a recommendation to use the lowest setting.

Ask your installer to choose the setting for your system. Do not treat it as a recommended tap temperature or change it just to make the displayed percentage look higher.

Why does the cleansing cycle matter?

The cleansing cycle is a regular heating cycle that helps control Legionella bacteria in stored water. It heats the tank more fully than normal day-to-day heating.

Cleansing is enabled in standard settings. Heat Geek Mode allows it to be disabled, so using the advanced mode also requires attention to water hygiene.

Keep cleansing enabled. Do not disable it unless the qualified professional responsible for the system has assessed the risk and put a suitable alternative water-hygiene plan in place. Mixergy’s guidance states that responsibility for preventing Legionella rests with the user if cleansing is disabled.

What should I do now?

If your tank is working well and your installer has not recommended Heat Geek Mode, leave your existing settings in place.

If the mode is already active, ask your installer to explain the settings they chose and how cleansing is managed. You do not need to keep adjusting it yourself.

If you are running short of hot water or the displayed level drops unusually quickly, tell your installer what happens and when. They can check the temperature settings alongside the way your system heats the tank.

Tenants should report these issues to their landlord or housing provider. Avoid changing the heat source or cleansing settings while trying to solve them.

Common questions

Do I need Heat Geek Mode if I have a heat pump?

No. Your tank can use a heat pump with its normal settings. Heat Geek Mode is an optional advanced setting that your installer should assess for your system.

Will Heat Geek Mode always reduce my bills?

No. Savings depend on how your system is set up and how much hot water you need. Your electricity tariff also affects the cost of heating.

Why can I not see Heat Geek Mode?

It is only available when Heat Pump is selected as the heat source. Do not change the heat source to reveal it. Ask your installer whether your system is suitable.

Why does my hot-water percentage fall quickly?

One possible reason is that the minimum output temperature is close to the target temperature. A little cooling then takes water below the limit for counting it as ready to use. Ask your installer to check rather than lowering the setting yourself.

Can I turn off cleansing to save energy?

Keep it enabled. Cleansing helps control Legionella bacteria. Disabling it needs a professional assessment and a suitable alternative water-hygiene plan; it is not a routine energy-saving adjustment.