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Hot Water Wire FAQs

What is the hot water wire?

The Hot Water Ripple Control system was introduced in the 1950s. It helps manage electricity load during busy or peak times of the day. These high load times are caused by all of us using electricity at the same time, typically during breakfast and dinner. To make sure the electricity network isn’t overloaded, we turn off supply to electric hot water cylinders at these peak times using the Hot Water Ripple Control.

The Hot Water Wire system had a dedicated wire on the network which supplied the hot water cylinders. When needed, Alpine Energy was able to turn power off to all hot water cylinders connected to that wire. This is typically done during peak load periods. New technology such as smart meters and ripple relays means we can now turn the supply to hot water cylinders on and off without the need for extra wires on the network.

What is ripple control?

Ripple control is the most common form of load management and is used in many countries worldwide. It works by sending a high frequency signal through the power network, which will turn off non-essential load, if this is enabled at the customers property. Customers who opt into ripple control can profit from reduced power rates.

The power network is built to support and deliver the highest electricity load used at any one time. By reducing this electricity load peak, Alpine Energy can keep the cost of building and maintaining the network lower for everyone.

What is a ripple relay?

A ripple relay is a piece of equipment used to remotely switch load off and on. The ripple relay is able to receive a signal through the power network, and turn specific electric appliances off – such as hot water cylinders.

Why is the hot water wire no longer needed?

Historically, Alpine Energy turned the power on and off for the hot water wire, and everything connected to that wire had or did not have electricity. Modern technology enables us to control the electrical load at the meter, rather than at the network level.

Why did Alpine Energy need to change the hot water system now?

We have recently noticed multiple faults related to the old hot water system. Rather than fixing an old, failing system, we have decided to move everyone to the modern equivalent. This will improve the overall reliability and safety of everyone’s hot water supply.

Where was the hot water wire de-energised?

The hot water wire is still in use in Timaru and Temuka. Only a small number of customers were connected to the hot water wire. Outside of Timaru and Temuka, the hot water wire had already been deenergised some time ago.

How long did this project take?

Originally scheduled from June 2024 to December 2024, we were thrilled to have it completed ahead of scheduled in early September. By implementing streamlined processes and leveraging valuable insights gained during the project’s early stages, we were able to significantly accelerate our progress.   Key improvements included enhanced pre-inspection data analysis, and more efficient tracking of de-energised and/ or removed assets.

How did Alpine Energy fix the problem?

Many properties already have smart meters installed, in which the hot water supply can be controlled remotely. At properties with an analog meter, we installed a ripple relay either at the meter board or on the pole. Think of this as a switch that we can turn off and on remotely. The ripple relay will only control power supply to your hot water cylinder, not to your whole property. Alpine Energy can send a signal through the network that is identified by the ripple relay/ smart meter to “turn on” or “turn off”.

What is still left to do?

The hot water wire has been de-energised but it is still on our poles and in our cable ducts. Over the next year we aim to remove the hot water wire from the network.

We have identified a few properties where the hot water cylinder is supplied with electricity through other non-standard configurations. We aim to bring these up to standard within the next year as well. This will make your power supply safer and more reliable. It will also make fixing faults on our network easier and faster for our crews. Affected customers will be contacted directly.

My hot water is off – what do I do?

Give us a call on 0800 66 11 77, send an email to mailbox@alpineenergy.co.nz or fill out the online faults form. We can check your address against our register to see whether we recently removed the hot water wire in your area.

I called an electrician but my outage was due to Alpine Energy. Do I get reimbursed?

At Alpine Energy we always strive for a fair resolution. Please talk to us about any reimbursement claim you wish to make. Please note that we will not be able reimburse any cost that is related to a fault out of our control.

If you are unsure whether a fault or hot water issue is related to the network or something internal, give us a call for a free assessment by our competent faults team. 0800 66 11 77.

I’m an electrician – how can I help?

If you receive any calls regarding power outages or hot water cylinders not warming up, please get in touch with Alpine Energy. We can check the address against our register to see whether we recently removed the hot water wire in the area. This will ensure a more efficient response.