Cost of gas as against electricity?

[JAD]

I have just moved into a house with 'economy 7' up and running. It is my understanding that this is only economical if you actually use energy at night whenever possible or else you could actually end up paying more?
I have set the washing machine and dishwashers on timers but was wondering if it would be cheaper to heat the hot water cylinder with the emmersion heater on a timer at night (for the morning) rather than using the gas boiler for this?
One other factor is that I have an old gravity fed hot water system and so the absence of a motorised valve means that the water heats whenever the boiler fires up.

Any thoughts would be gratefully received.

 

[Agile]

Generally its cheaper to heat anything with gas.

However, if your boiler is an old inefficient model then the off peak electric immersion will probably be cheaper.

Tony

 

[croydoncorgi]

IF the immersion heater is at the BOTTOM of the cylinder, it would be worth running it on a timer so that you get a tank full of hot water on cheap electricity. But (obviously) if you have no control of the hot water while the CH is on (ie. in winter) you will gain little or nothing from using electric water heating.

If the immersion heater is mounted through the top of the cylinder, it will probably only heat the top third or half of the water, so not worthwhile.

Your money would be better spent on a zone valve, cylinder thermostat, etc, so that you only heat the water when necessary.

 

[JAD]

Thanks for that guys.
I'll have to think this through carefully.