Frost protection

Frost protection is an automatic feature that helps protect the water in your Mixergy tank against freezing. You do not need to switch it on or set a heating schedule for it.

It only works while the tank has electrical power. Leave the tank switched on at the mains during cold weather, including when you are away.

How does it work?

The tank monitors the temperature of the water inside it. If the water temperature falls below 5°C, it starts heating. Heating continues until the water reaches 15°C throughout the tank.

This warms the water enough for frost protection. It does not make it hot enough for your usual showers or baths.

Why is my tank heating outside its schedule?

Frost protection can start even when your usual heating schedule is not due. It responds to cold water in the tank, so it does not wait for the next scheduled heating period.

It is more likely to run if the home has been unheated for a long time or the space around the tank is very cold.

If the water has become very cold, this extra heating is expected. You do not need to change your schedule to stop it.

What should I do before going away?

Leave the tank connected to electrical power. If you want to pause your normal hot water heating while you are away, use Holiday mode in the Mixergy app. This pauses your usual schedule without cutting power to the tank.

1. Open the Mixergy app, sign in and select your tank.
2. Open the main menu and select Schedule.
3. Tap the aeroplane icon at the top of the screen.
4. Enter your departure and return dates, then confirm them.

Your normal scheduled heating resumes when the holiday period ends. Frost protection remains available while the tank is powered.

If you do not have access to the app, ask your installer how to pause normal heating while keeping frost protection available. If you rent, contact your landlord or housing provider.

What if the home will be empty for a long time?

Ask your installer for advice about preparing the property for cold weather. Tenants should ask their landlord or housing provider.

Frost protection protects the water in the tank. It does not protect every pipe or the rest of your heating system. You still need a plan to prevent the wider property from freezing.

When should I ask for help?

Contact your installer or Mixergy Support if:

• Frost protection keeps running even though the home and the space around the tank are normally warm.
• The tank cannot heat, including if it has lost power or displays a fault.

If you rent, report the issue to your landlord or housing provider. Describe what you have noticed and include any message shown in the app. Do not remove the tank’s covers or attempt electrical work.

Common questions

Do I need to switch frost protection on?

No. It works automatically. Leave the tank powered so it can monitor the water temperature and heat when needed.

Will frost protection give me hot water for a shower?

No. Its heating target is 15°C, which is below normal hot-water temperature. You still need your usual schedule or a Boost to heat water for everyday use. A Boost is a request to heat extra water.

Does it work without an internet connection?

Yes, provided the tank has electrical power and is operating normally. Losing internet access is different from switching off the power supply.

Will it run while Holiday mode is active?

Frost protection remains available while the tank is powered. Holiday mode pauses normal scheduled heating; it does not disconnect the tank’s electrical supply.

Does it protect the whole house against freezing?

No. It is a tank function. Your pipes and room-heating system need their own protection. Ask your installer, landlord or housing provider what to do if the property will be empty during cold weather.