Electricty use

Can anyone adise. Got a water heater on the wall. Estate agent says to keep it on all the time

as switching off and on costs more? Confused. Any advice is apprciated .

Tel the agemt to stick to selling properties as he knows nothing about electricity.

Power is only consumed when the heater is switched on.   Keeping water hot when it is not needed means that it is loosing heat whilst just being stored and thus being re.heated.

Although it can be inconvenient, the best way to use the least electricity is to only heat the water for when it is needed and then switch off, until next time.  Cold water in the tank is not losing heat

Also, often thermostats are set to an unnecessary high level  If you need to add cold water to be able to use the heater then the thermostat is too high and you are wasting power.

It depends how often you are there. A heater generally uses less energy to top up, or maintain temperature then it does to heat the whole tank from cold. If you are only using it every few weeks or months, then it'll probably be cheaper to switch it off.

Fartharded,

Sorry, but heating anything, but let’s say water, by 1ºC uses the same  amount of power whether it is starting at 0ºC   or 30ºC, but keeping it warm when not need is wasting electricity / money.

Raising the temperature of 1cc of water by 1ºC uses one calorie. SEE BELOW AT ‘A’

See:-       https://www.cse.org.uk/advice/energy-saving-tips/energy-mythbuster

It’s better to leave the hot water heater on all the time, rather than turning it on and off.

This is a very common myth. But in fact, you really don’t need to be heating your water all the time. Your immersion heater or boiler will heat up hot water which is stored in a tank. As long as the tank has a good insulating jacket, it will keep the water hot all day, without needing to be constantly reheated. You can use a timer to heat your water for an hour or two each day just before you would usually need hot water for baths or showers

See:-  http://whatis.techtarget.com/definition/calorie-cal

‘A’

QUOTE:_    

When 1 cal of heat energy is transferred to one gram (1 g) of pure liquid water, the temperature of that sample of water is raised by one degree Celsius (1º C) or one degree Kelvin (1º K,    When the temperature of 1 g of pure liquid water falls by 1º C or 1º K, that water gives up 1 cal of heat energy.

Raising the temperature of 1cc of water by 1ºC uses one calorie.

This message was last edited by johnzx on 21/11/2015.

Wouldn't a gas combination water heater be the answer? Of course if you had gas central heating with a combination boiler then you wouldn't be asking the question, electricity heating has always been more expensive in respect of heating water in my experience.

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Back to water heating!

This serious replies here have all seemed to addressed the question by giving UK type answers and quoting data from UK energy websites that are of course relatively worthless here in Spain. In Spain we don't have copper water tanks fitted with insulating jackets -  mostly we have wall slung Thermos typically 150 ltrs fitted with a immersion heater and thermostat. 

The real answer lies with what you are going to consume - In our house, lived in full time, with at least 2 showers taken daily, the hot fill washing machine on most days and the dishwasher on every other day i believe we are better off leaving it on constantly. I've worked it out that If I were to turn it off at night it would cost 6.3 kwh to reheat the next morning

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This message was last edited by Tadd1966 on 21/11/2015.

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How you use the water and how many of you there are!

in Spain apartments like mine, are fitted with a 50 to 100lt elec boiler, mine is 88lts, and for the 2 of us, I have a timer fitted, to be on 1 hour in the morning and 1 hour in the late after noon, this allows dish washing, we use a sink dishwasher and hands, also showers for two, as many apartments and newer washing machine only use cold water feeds.

in very hot weather our boiler is in a good position and can be bearable for a shower without heating, and to wash the pots, a kettle top up is good enough.

and if you need water use the override time push it will be hot within 20 mins or so.

though coming in now we don't have gas as a option.

always looks expensive for heating in Spain I spent around a 1000e for my elec last year, a cold one too, I have a 2 bed apartment, with a long outside wall as well, though I have double glazing.

hope this helps!

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We have cleaned the thread, not of insults or abuse so much, but more of irrelevant comments and a quick derail of the thread. Those involved have received a PM.  For the rest please ignore this and continue with the thread.

thank you

Think of an electric water heater as a big slow to heat kettle,  now do you put your kettle on a few day's before you want a cup of tea, it is the same principle, johnzx is perfectly corect in what he's saying,  uk data is perfectly acceptable to this scenario!!

Thanks Pete. 

Team GB ;  

This serious replies here have all seemed to addressed the question by giving UK type answers and quoting data from UK energy websites that are of course relatively worthless here in Spain. In Spain we don't have copper water tanks fitted with insulating jackets –

...............  mostly we have wall slung Thermos typically 150 ltrs fitted with a immersion heater and thermostat.  

And if you were to take it apart you would find a copper tank, with an immersion heater and thermostat, which is insulated with a 'jacket' between the storeage tank and the outside metal/plastic cover..    Just like anywhere in the world, which has that type of installation.  Only  ‘on demand’ systems do not comply.

So when you leave the power on, and the thermostat keeps switching on and off,  you use more power.

I'm not going to argue with science or physics, I was just saying what works best for us - there are senarios governed by usage when it is not cost effective to turn it off.

I do agree with you though that most people have thier thermostat turned up far to high

If you need a bath at 3 in the morning then leave it on,otherwise get yourself a plug in timer set it to come on 1 hour before you require the hot water job done works for me anyway.

Team GB there are scenarios governed by usage when it is not cost effective to turn it off.

I did say that in my first post:- 

"Although it can be inconvenient, the best way to use the least electricity is to only heat the water for when it is needed and then switch off, until next time.  Cold water in the tank is not losing heat"