Immersion heater - leave on or timed?

[Marnhullman]

Thanks to several forum members I have successfully? replaced an immesion heater in my daughter's flat. I would now be interested to have opinions as to whether it is more economical to leave the heater on permanently or use a timer?

Regards

 

[kevplumb]

personal opinion (for what its worth ) if the cylinder is well insulated
leave it on it will cycle on the stat
so not permanantly on

 

[Kingsway]

leave turned on

 

[oilman]

I'd like to see objective justification for leaving a heater on permanently rather than anecdotes or opinions. ANYTHING left switched on and maintaining ANYTHING at a high temperature will use more power than at a lower temperature.

If you're out all day, why have the heater on? You go off for the weekend, why leave the heater on? You sleep most of the night (unless your name's kevplumb), why leave the heater on?

If the stat's not always switching it will last longer, if the heater's not always on it will last longer. This is basic physics.

Dear Sir,
Please leave your heater on all the time.

Yours faithfully,

Immersion Heater Mnufacturers and Maintainers Society.

 

[Marnhullman]

Thanks - now totally confused since both options seem logical.

1. Leave it on all the time and the water doesn't get so cold so less power is needed to heat it up

OR

2. Put it on a timer and the heater lasts longer and you're not heating water when you don't need it

I guess the only way is to try both options, since the timer is in situ, and see what difference they make to the bill.

Thanks again - now for another, hopefully final (for now), post on another issue!

 

[Malc]

Just to point out the physics of this is:

If you only heat when need then the average cylinder temperature over the 24hrs is lower. Hence the heat lost to the airing cupboard is lower since this is related to the temperature difference. Therefore you use less electricity if you only heat when required, i.e. use a time clock.

You might also want to consider economy 7 if you are using electricty for hot water. It depends on your usage as to whether you make any savings since E7 day units are more and standing charge is more. If you put your washing machine, dishwasher, etc. on timers, your hot water on a timer and have a large enough tank to last the day then you may save.

I used to do this. Saved about GBP 10 pa. Only used electricity for HW in the summer though. Now I'm switching to oil and electricity suppliers and E7 works out more expensive.

 

[Marnhullman]

Malc

Thanks. Looks like the cost saving is very marginal.

Regards