Immersion Heater, leave on or turn off advice please?

Amelia36

Hi

I only have a immersion heater to heat my water and want to know if i should be leaving it on all the time or turn it off and on when i need water, i have always switched it on and off but wonder if its just as cheap to leave it on all the time, can anyone offer me advice please?

Thanks

mwbrown

My parents used to turn the immersion heater on and off all the time and i told them it would be cheaper to leave it on all the time.... they wouldnt believe me that it would be cheaper to leave it on.

but i proved it by monitoring the electric usage over 6 months - and to be honest it was cheaper to leave the immersion on due to the fact the when the immersion was switched on and off it used more electric to heat the water (rather than leaving the heater on, it just continually heated water when required after using some hot water when the temperature dropped in the tank..)

Personally i would always leave the immersion heater on (my dad still does to this day) and the only time he turns it off is when he goes on holiday.....

HTH

Mike

Amelia36

Thanks for that Mike i will try it and see if it saves me money!

laurax_2

As Mike said, leaving it on it a lot cheaper then switching it on and off when needs be, for the reasons he stated (pointless writing it all over again! lo)

Cardew

laurax wrote: »

As Mike said, leaving it on it a lot cheaper then switching it on and off when needs be, for the reasons he stated (pointless writing it all over again! lo)

I am sorry but that is completely and utterly incorrect.

Covered countless times on MSE.

Please, Please, don't trot out the stupid concept that it takes more electricity to warm something up from cold than to continually top it up.

If that is the case(leaving it on all the time) why don't you leave your kettle or saucepan of water simmering all the time?

If you went away for a year, would you leave your water on constantly? How about a month? A week? A day? At what point does the law of thermodynamics not apply?

Can people not understand the concept of heat loss? The warmer you keep an object(including a tank of Hot Water) the greater the heat loss from that object - it is a fundamental principle of the laws of thermodynamics.

As for experiments of the 'I have proved it' variety! Well put yourself up for a Nobel prize for Physics as you have just disproved everything that scientists have relied on for years!!!!

laurax_2

Well this is from my person experience. If your going to use your hot water maybe 3 times a week and not a handfull of times each day then fair enough. I used to turn my emersion heater on for an hour in the morning and an hour in the evening. From doing this to keeping it on all day my eletric bill was noticably lower!

Andy_WSM

Cardew wrote: »

I am sorry but that is completely and utterly incorrect.

Covered countless times on MSE.

Please, Please, don't trot out the stupid concept that it takes more electricity to warm something up from cold than to continually top it up.

If that is the case(leaving it on all the time) why don't you leave your kettle or saucepan of water simmering all the time?

If you went away for a year, would you leave your water on constantly? How about a month? A week? A day? At what point does the law of thermodynamics not apply?

Can people not understand the concept of heat loss? The warmer you keep an object(including a tank of Hot Water) the greater the heat loss from that object - it is a fundamental principle of the laws of thermodynamics.

As for experiments of the 'I have proved it' variety! Well put yourself up for a Nobel prize for Physics as you have just disproved everything that scientists have relied on for years!!!!

Cardew is absolutely correct, of course, but it is also worth pointing out that the cost of leaving it on (assuming the thermostat is operating correctly & the tank is sufficiently lagged) is only minimally higher than turning it on only when you need it - and of course you have the convenience of always having hot water available rather than having to wait an hour or plan ahead.

Modern tanks have to be insulated to a level that prevents more than just a few KW/h of heat escaping in a 24 hour period, so that's about 20-30pence extra in monetary terms for the convenience of 24/7 hot water.

Cardew

Andy_WSM wrote: »

Cardew is absolutely correct, of course, but it is also worth pointing out that the cost of leaving it on (assuming the thermostat is operating correctly & the tank is sufficiently lagged) is only minimally higher than turning it on only when you need it - and of course you have the convenience of always having hot water available rather than having to wait an hour or plan ahead.

Modern tanks have to be insulated to a level that prevents more than just a few KW/h of heat escaping in a 24 hour period, so that's about 20-30pence extra in monetary terms for the convenience of 24/7 hot water.

Agree 100% in fact probably less than 20p to 30p a day extra.

It is also relevant that the heat lost from the tank is not wasted for much of the year as it warms the house(albeit at daytime electricity prices!) which is why tanks are often in airing cupboards.

It is just these, frankly stupid, claims to have proved leaving it on 24/7 is 'much cheaper'(see above) that are so misleading on a Money Saving Website where people come for advice.

davidgmmafan

I chuckle a little everytime I read the kettle example

Andy_WSM

Cardew wrote: »

It is just these, frankly stupid, claims to have proved leaving it on 24/7 is 'much cheaper'(see above) that are so misleading on a Money Saving Website where people come for advice.

Equally annoying though are the claims that it costs hundreds of pounds a year extra to leave it on - so people have all the inconvenience of waiting for hot water, when the reality is it really doesn't cost much at all.

I know the site is all about saving money, but sometimes I do wonder if people take things too far for the sake of pennies.

gord115

I leave my car ticking over all night so I don't waste fuel warming it up...