Having access to the spot price of generation means you can move load around to cheaper times of day, and are able to pay less without doing less. Yay!

But it’s also important that you stay safe while you make changes to your household habits.

Recently, a number of cases of Legionnaires disease have been reported in the media, sparking conversation among some Flicksters about whether it is safe to turn your hot water cylinder on and off to make the most of fluctuations in the spot price..

Lynne from Taranaki wrote to us: “We all want to save money on our electricity bill and Flick really helps us to make personal choices as to how much/when we use power. My concern relates to being ‘safe’ while making those savings.”

Like Lynne, we feel it’s our responsibility to give you the right information and flag something that may potentially put you and your family at risk.

Fiddling with your hot water cylinder can cause the water to drop to a temperature where it stagnates and legionella bacteria grows.

Since the two recent cases of Legionnaires disease in the Hawke’s Bay, the District Health Board is warning people against turning down their hot water cylinders to save money – we wholeheartedly agree with this advice.


What is Legionnaires disease?

“Legionnaires’ disease is transmitted by inhalation of aerosolised water and/or soil contaminated with the bacteria. It is not airborne and it is not transmitted from person to person. Sources where temperatures allow the bacteria to thrive include hot-water tanks, cooling towers, and evaporative condensers of large air-conditioning systems, such as those commonly found in hotels and large office buildings. Though the first known outbreak was in Philadelphia, Pennsylvania, cases of legionellosis have occurred throughout the world.” via wiki.

Update – 24.07.15 

Peter asked us via Facebook: ‘Is safe to turn the HWC off say at 7 am then on at 11pm. (Where the thermostat has not been turned down but is set to 60deg C)  What is your view on the safety of this practice ?’

EECA do recommend cylinders need to reach 60°C only once a week to kill Legionella. , however there are other things to consider when turning your HWC on and off, including whether the cylinder is already ‘controlled’ by the network company.  Also, if you don’t know how old your cylinder is, it may cause it to malfunction.  In terms of whether it is safe to turn off the cylinder early morning and back on late at night, that’s at the users’ discretion.  You can buy aftermarket timers, which can be installed by an electrician, however these won’t respond to pricing signals.  Plus there’s no remote control or knowing when a price spike might occur.  Something like a Belkin Wemo is a great addition to changing your load, but they aren’t big enough to assist with managing your cylinder.


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