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Does switching off your geyser really save electricity?

Recently I attended a talk on geysers and was blown away when I heard that turning off your geyser actually doesn't save electricity and therefore actually doesn't save you money. Really? These were professionals talking but, still, I thought I'd turn to trusty Google to confirm whether this outlandish statement was the truth.
Turns out they're right - in most cases anyway!

For those of you who, like me, didn't know much about the technical side of the 'ol geezer, here's the quick and dirty:

  • Your geyser is like a big kettle. It has an element inside that heats the water up to a set temperature.
  • When a hot tap is turned on, hot water is released from the geyser and cold water rushes in to replace it. As the water temperature in the geyser has now decreased, the element kicks in to heat the water back up to the set temperature.
  • When no one is using hot water the temperature of the water should remain the same as no cold water is being let in. However, heat will "leak" out of the geyser into the surrounding area and the rate of the heat leak depends on the quality of your geyser's insulation. These heat leaks cause the water temperature inside the geyser gradually to decrease and the element kicks in to reheat the water when necessary.

    So, the argument for turning your geyser off when you are not at home is that the element will not periodically kick in to heat up the water and, therefore, you'll use less electricity. But this doesn't take into account that once switched off, the water in the geyser eventually cools down completely and, when switched on again, a huge amount of energy is required to heat the water back up to the set temperature. In most cases, more energy than if the element was periodically kicking in throughout the day.

    The factors that affect the energy consumption of your geyser are:

    • The type and condition of your geyser;
    • How much hot water you use; and
    • How often you use it.

    So the best ways to help your geyser conserve energy are the following:

    • Only use the hot tap when necessary - washing hands, splashing your face etc. can be done with cold water only;
    • Use less hot water when you do use it - short showers or shallow baths rather than long showers and deep baths;
    • Turn your geyser off when going away for a few days - then it makes it worth it;
    • Ensure your geyser and water pipes are properly insulated - ensuring that heat leak is lessened.

    So there you have it.

    Happy geyser energy conserving!
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About Jennifer Paddock

Jennifer Paddock is a specialist sectional title attorney and managing partner of Paddock, sectional title and home owners' association specialists.
Heather Parker
In fact, the most effective thing seems to be to put your geyser on a timer (it's socially thoughtful to time it to kick in during low-usage periods), and insulate it well. Then the cooling is minimal (because of the insulation) and the heating is limited to a couple of hours a day. I've cut my electricity consumption by about 30% this way.
Posted on 27 Jun 2013 10:55
Altus Pienaar
This article is based on theory but in practice you can save as much as 50% on your electricity bill. I switch my geyser of after the last shower at around 10 and back on around 5 in the evening. I boil water in the kitchen for dishes and my electricity dropped from an average of around R750 to R350 and this with the added use of a submersible pump that was running for a full day at least every second or third day during summer to irrigate my vegetables.My geyser is installed on the ground and there is a dramatic loss of heat into the plumbing. Check for heat loss by touching your geyser and if it feesl cool to the touch it is well insulated. To prevent heat loss in the plumbing mount you geyser at the highest point. Warm and less dense water migrates to the highest area and if your geyser is on the ground you will constantly loos heat with hot water migrating up into the plumbing. A geyser mounted high up will keep the hot water till you open the tap.
Posted on 29 Aug 2013 12:10
Farrell Mackennon
There is some very useful and practical advice here and I have experienced myself a reduction in electricity charges simply by insulating the central heating geyser so it doesn’t lose so much heat. It’s important to make sure your geyser is insulated well as the amount of heat that can be lost can be quite significant, the newer your model of geyser is then the more effective it will be at keeping the water hot for longer, but even the older models are effective at keeping hot once they have been insulated well.
Posted on 18 Feb 2014 09:49
Aaron Mathe
I understand the matter of theory of the article,but according to my experience as a qualified electrician you can check my page on Facebook,it's called Power Saving Electrical Solutions,it's better you get your 20 amps timmer,and you set it on times you wish to use hot water,but it must be earlier than you wanna use your water,the main thing,don't forget to buy a geyser blanket when you install that 20Amps timmer
Posted on 28 Jan 2015 07:43
lester mulligan
turning your geyser on and off will definitely save you electricity, it takes the same amount of energy to re heat your geyser compared to maintaining your temperature and leaving it on, the element in the geyser is controlled by a thermostat , when the temperature reaches a certain point the thermostat will switch the element on and off continuously ( remember that the amount of energy drawn by the element is always drawn at 100% of the kilowatt rating of the element,) not that that makes much sense... what sould help to increase the efficiency of the whole system would be to invest in a geyser blanket or just get some old material and cover your geyser if possible, this will keep the heat in,, especially with winter coming up,
Posted on 23 Mar 2016 15:01
Patrick Gibson
Actually disagree, using a timer is a much better idea - when the geyser is left on all the time, the thermostat switches on and off using hysteresis based on the water temperature, but when it is on it still needs the same amount of power irrespective of the temperature. So lets say for example it is on using a geyser for 1 minute out of every 6, that equates to 4 hours a day. When compared to using a timer that switches on for 1 hour and then off completely (so water can be used later), that equates to 25% saving on the amount of power used without the timer. My electricity bill went right down once I installed the timer.
Posted on 19 Aug 2016 14:04
Roeks Griessel
Use a blanket and set the thermostat to 56 Deg C in my area. The biggest waist is to over heat the water. So when you shower or run a bath you should not add cold water to cool it down. Let the geyser run 24/7 at the correct Degrees C for your climate conditions.
Posted on 21 Aug 2016 10:07
Francois Van Niekerk
Tank-less advantages – Gas Geysers.• Immediate & Long term energy savings: Though a tankless water heater typically costs more initially ( Not with Instant Gas and Power ), it usually costs less to operate because of lower energy use—since it only heats water when required instead of continuously maintaining a tank of heated water. Even homes or buildings with high demand for hot water may realize some level of savings. If instant hot water at taps at limited hours is a priority, a recirculation system can be accommodated by using an aqua stat and timer to decrease the added heat loss from the recirculation system. If the storage tank of an electric heater is highly insulated, so that the outer surface of the tank is only slightly warmer than the ambient air, the savings with a tankless heater is less.• Savings in water use: Users in remote points in the building do not have to run the hot water as long waiting for it to get to the faucet.• Unlimited hot water: Though flow rate determines the amount of hot water the heater can produce, it can deliver it at that flow rate indefinitely. However, this can also be an ecological disadvantage, as running out of hot water limits use, but a tankless heater provides no such limit.• Less physical space: Most tankless water heaters can be mounted on a wall or internally in a building's structure. This means less physical space must be dedicated to heating water. Even systems that can't be mounted on walls take up less space than a tank-type water heater.• Reduced risk of water damage: No stored water means there is no risk of water damage from a tank failure or rupture, though pipe or fitting failure remains possible.[8]• Temperature compensation: A temperature compensating valve tends to eliminate the issue where the temperature and pressure from tankless heaters decrease during continuous use. Most new generation tankless water heaters stabilize water pressure and temperature by a bypass valve and a mixing valve incorporated in the unit. Modern tankless are not inversely proportional, because they regulate the amount of water they heat and discharge, and therefore stabilize water temperature by using a flow control valve. Temperature change, not flow speed, is the issue the water heater must address. The wider the temperature rise, the less flow from the unit—the smaller the temperature rise, the greater the flow. The flow control valve, in conjunction with thermostats, maintains a stable temperature throughout the use of the unit.• Safety: Tankless Water Heaters precisely control water temperature, which means dangerous temperature levels and spikes are less likely.[9]An additional safety advantage stems from reduced exposure to dissolved toxic metals, which tend to occur at higher concentrations in hot water which has resided in a conventional water heater tank for significant periods of time.
Posted on 23 Aug 2016 21:41
This article is totally plagiarized from the Isotherm website!!
Posted on 9 Dec 2018 20:05
All is well said,but I turn off the power as soon as the 1st shower begins. We are only two in the household and the power is on for 2 hours a day and we save 40% on totol electric bill.
Posted on 15 Aug 2019 11:46