ABOUT THE TRIAL

Why are you doing this trial? Hot water can account for up to 30% of your household power usage. By optimising its energy use with the device we're testing, we're aiming to reduce pressure on the national grid and reward you for taking part.
When does it start? Installations will begin from 3 June 2025 with the devices being turned on from 26 June 2025. The trial will run for 6 months until 31 October 2025.
How will this affect me? Throughout the trial, you can use your hot water as usual. However, a Rinnai device will be attached to your hot water cylinder for the next 6 months to help us manage and optimise your hot water heating.
When will the account credit be applied? We'll apply $100 account credit once the device is installed. The remaining $150 will be applied after the device is removed and you’ve completed the trial.

THE DEVICE 

How does the device work? It connects to a cloud-based platform via the cellular network, learning your household’s usage patterns and syncing heating to off-peak times. All while making sure you have hot water when you need it.
Are the devices safe? Yes, these devices are safe and Rinnai NZ has confirmed they meet all regulatory requirements. 
Will I own the device? No, you won’t own the device and Rinnai NZ will remove it after the trial ends.

INSTALLATION

What's involved?

The installation is straightforward and will take less than an hour. A Rinnai NZ nominated professional will contact you to arrange an installation appointment.

A small device (size 175 x 125 x 80 mm) is attached on or near your hot water cylinder (see illustration below). At the same time, the installer will optimise your hot water cylinder – insulating it if needed to help it run more efficiently. This will be left on your cylinder after the trial.

They will explain how the device works and answer any questions you may have.

 

Illustration of a hot water cylinder with a small device attached to it.

Why does my cylinder setup need insulation? Insulating the hot water pipes connected to your cylinder helps reduce heat loss and improves energy efficiency. If your pipes aren’t already insulated, we’ll make sure it’s done when we install the device. After the device is removed, we will leave the insulation in place, unless you ask us to remove it. 
Will this affect my existing hot water cylinder warranty? No, this device has no effect on any warranties that are already in place. 
How do I change the installation date? If you can’t attend on the agreed date, please contact your installer using the contact details provided during the original installation booking. They’ll arrange a new time that works for you.
What if there is any damage to my wall or hot water cylinder? While unlikely, any minor damage will be repaired and restored to its original condition by Rinnai NZ nominated professionals who handle both the installation and removal of the device. They will not be responsible for any pre-existing damage. 

HOT WATER

Will I still have hot water when I need it? Yes, you shouldn’t notice any difference.
How will you manage my hot water? As part of the trial, we will remotely control and manage the device and system. This is to test how your hot water heating can be optimised, to heat more of your hot water at off-peak times. 
What happens if I run out of hot water?

If you’ve run out of hot water, please refer to this guide to troubleshoot common causes. If you still don’t have hot water after following these steps, please call us on 0800 10 18 10. Select ‘Electricity’, then ‘Faults’ from the phone menu, and let the Customer Service Specialist know you're part of the Smart Hot Water trial.


END OF THE TRIAL

Can I opt out? Taking part in the trial is completely voluntary. You can withdraw at any time by contacting smarthotwatertrial@mercury.co.nz. Note, this will mean you won't receive the second $150 account credit. The device can be remotely deactivated, so you won’t need to wait for its removal to return to normal operation. A Rinnai NZ appointed technician will contact you to arrange a time to remove the device.
What happens if I have to move? We ask that you join the trial only if you expect to stay in the same property until November. If you need to move, please let us know as soon as possible at smarthotwatertrial@mercury.co.nz so we can arrange for the device to be removed.
When does the trial finish? The trial will finish on the 31st of October 2025, with the device being removed from your cylinder during the month of November 2025.
Will the device be removed? Rinnai NZ will contact you at the end of the trial in November to arrange an appointment for device removal. This process will take less than an hour. Apart from some small holes on the wall from the screws, and extra insulation (that makes your hot water cylinder run more efficiently) everything will be left as it was before the trial.

NEED HELP?

If you couldn't find the answers to your questions or need further support, please contact us at smarthotwatertrial@mercury.co.nz.
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