GCH vs Electric which is cheapest way to heat our water tank?

Owain_Moneysaver

If you have gas central heating and hot water, why do you have an Economy 7 electricity tariff at all?

Economy 7 daytime electricity is more expensive, and there is a smaller range of tariffs/providers to choose from. It's usually only worthwhile if you have significant overnight and low daytime electricity use.

Biscuit_Tin

Owain_Moneysaver wrote: »

If you have gas central heating and hot water, why do you have an Economy 7 electricity tariff at all?

Economy 7 daytime electricity is more expensive, and there is a smaller range of tariffs/providers to choose from. It's usually only worthwhile if you have significant overnight and low daytime electricity use.

Incorrect. It varies so much by supplier/tariff & region.

Easiest way to compare is via a comparison site, run first as a E7 customer and then again as non-E7 customer (by adding day & night usage together)

We have GCH & hot water, have E7, and do not use a significant low rate amount; in fact we use about the same in an average low rate hour as we do in an average normal rate hour. We are are no worse off on E7.

Pincher

I always wondered why Victor Frankenstein worked at night.
Now I know! It's cheaper to create your monster by Economy 7 electricity!

Biscuit_Tin

JethroUK wrote: »

We have been heating our water tank via electric emmersion heater element 2 hours per night during economy 7
The element has blown
Shall bother fixing it or just put GCH on 2 hours in tye morning to heat the water tank up?
GCH vs Electric which is cheapest way to heat our water tank?

Compare how much you pay for 1kWh of gas compared to 1kWh of electricity. :eek:

Even if you allow for say 60% efficiency of an old gas boiler (newer ones are more efficient than this) you will still see gas is cheaper than normal rate electricity.

Using low rate electricity, there may not be much difference depending of the exact tariffs you have.

yangptangkipperbang

JethroUK wrote: »

Actually dont give a monkeys about efficiency (input/output) and its totally irellevent to the question - and the only people that would think it rellevant dont actually understand "efficiency" at all
It is more "efficient" to walk to the moon than go in a rocket is about as much of an example as I can think off

Why ask the question if you seem to be already decided about the answers you will accept ? - apart from being rude to those who bothered to respond to your query .........

JethroUK

Pincher wrote: »

On the other hand, I bought two titanium (so Plumbcenter claimed) immersion elements for a Gledhill Pulsacoil thermal store for about £150. Got the plumber to replace both elements. The 10+ year old elements were so stubborn, that the removal took so much twisting and banging, that the cylinder leaked, causing a minor flood down stairs, and eventual total replacement of the Pulsacoil thermal store, at a cost of £1,600.


So gas boiler gets my vote here.

My plumber said £100 to replace the element or £500 to replace the tank which will more than likely split - Gas me thinks )

JethroUK

Owain_Moneysaver wrote: »

If you have gas central heating and hot water, why do you have an Economy 7 electricity tariff at all?

Economy 7 daytime electricity is more expensive, and there is a smaller range of tariffs/providers to choose from. It's usually only worthwhile if you have significant overnight and low daytime electricity use.

I did some basic maths about 10 years ago and concluded
Daytime tariff is same on e7 (slightly higher standing charge)
Fridge/freezer uses enough to warrant the saving
We also do laundry at night
Maybe time to do more maths but I would be interested if you have any up to date maths on fridge freezer vs e7

JethroUK

yangptangkipperbang wrote: »

Why ask the question if you seem to be already decided about the answers you will accept ? - apart from being rude to those who bothered to respond to your query .........

I can ask a question without being subjected to "stock" claptrap about "efficiency" regurgitated by people that have just heard it from otjer people and that do not understand efficiency to such an extent that they use it regardless of its irrelevance?

In this case totally irrellevant (see my analogy) and disconnected to my question

ohreally

JethroUK wrote: »

My plumber said £100 to replace the element or £500 to replace the tank which will more than likely split - Gas me thinks

Since the immersion cylinder is out of use at the moment anyway, why not give it a try (removing element) and if it fails, cap off the pipes? Or is it old and in poor condition?

Pincher

Assuming 4p per kWh for gas burnt, and 70% efficiency boiler, you pay 4 / 0.7 = 5.7p to get 1kWh of heat in the water.

So, if your cheap overnight rate is 5p per kWh, then it is cheaper.

The top up immersion element only heating the top of the tank idea is a good twist. I did that when we replaced the boiler, which took weeks because of various delays (The builder said the cement wouldn't set properly because the weather was too cold, AFTER we disconnected the boiler!). It was good for a quick shower, but definitely not enough for a bath, so I started it 15 minutes before running the bath, and kept it on during. You end up forgetting to switch off all the time, so it's better to have it on a timer.