Efficient water heating???

giftbouquets

Hi,
I usually heat my water using gas central heating boiler. This is old and very inefficient. (I am in the process of saving for a new one) Since central heating is not needed for the summer, I have decided to heat water using electric water heater as I think this will be more energy efficient? My question is, will I use less energy just heating the water once or twice a day for an hour or so, or is it better to leave the heater on so that it just warms the water up as and when needed. Hope that makes sense.

barrymung

It depends...I assume by "water heater" you mean an immersion heater in the CH cylinder?

I'd say that if you heat a tank of hot water and then empty the tank doing loads of jobs all at the same time you'll save money.

If you heat a tank of hot water, use half and leave the rest sitting there for three hours you'll probably lose money.

barrymung

Whilst your boiler is old and inefficient, is it still reliable?

If so, it may be cheaper to keep using the old boiler and swallow the higher fuel bills.


Until very recently I was running a 35 year old boiler. The logic being it'd only cost £25 per year to have serviced and when it went wrong the repair bills were under £40.

Unfortunately, the heat exchanger rotted and I replaced it with a modern all singing all dancing combi. Now they want £60 per service and I hate to think how much when it breaks down.

giftbouquets

Hi,
Thanks for your reply. Boiler is not too reliable, has been repaired twice in the last year. Working O.k at the minute, but main problem is the cost - gas budget plan has gone up to £90 a month :mad: I tend not to use much hot water until the evening (shower is electric) so think I will try just putting the immersion on at this time and see how the bills go.

moonrakerz

If you are getting a new boiler heat your water with it, this is cheaper than electric; and leave it on all the time.
Make sure your hot water tank is properly lagged.

thescouselander

giftbouquets wrote: »

Hi,
I usually heat my water using gas central heating boiler. This is old and very inefficient. (I am in the process of saving for a new one) Since central heating is not needed for the summer, I have decided to heat water using electric water heater as I think this will be more energy efficient? My question is, will I use less energy just heating the water once or twice a day for an hour or so, or is it better to leave the heater on so that it just warms the water up as and when needed. Hope that makes sense.

I think you have got the wrong idea here. Your electric heater might be very efficient at the point of use but there is plently of inefficiency further up the line when the electricity is being generated.

First of all there are inefficiencies at the power station, energy losses when burning fuel to heat the steam, further losses atthe steam turbine and more losses at the generator it drives. Then there are the transmission losses over the national grid and associated transformer equipment.

Even if you have an old boiler I doubt it would be too much less efficient than using electricity once all the losses are taken into account. Also remember that electricity is much more expensive than gas so you will be out of pocket too.