Water heating on Economy 7

RebTech

(I have an energy supply problem described in another current thread but this is a separate issue, for the moment I'm pretending there's no prob.)

I'm currently on E7 and paying roughly twice as much on the day rate as the night rate. This is a modern flat and there's a large well insulated water cylinder. But I live alone and use very little hot water most days so I'm wondering whether, instead of using the night rate to heat the whole cylinder, I should just use the boost for 30 mins each morning. Do I need to run tests with meter readings or is the answer obvious (to some)?

molerat

Boost for 30 mins in the morning during off peak - on E7 all units used in off peak times are charged at the lower rate. You obviously need to know when your off peak times are and confirm your meter switches at the correct times including the BST/GMT difference. Usually fairly simple to fit a timer to the boost.
https://customerservices.npower.com/app/answers/detail/a_id/179/~/what-are-the-economy-7-peak-and-off-peak-periods%3F

footyguy

RebTech wrote: »

(I have an energy supply problem described in another current thread but this is a separate issue, for the moment I'm pretending there's no prob.)

I'm currently on E7 and paying roughly twice as much on the day rate as the night rate. This is a modern flat and there's a large well insulated water cylinder. But I live alone and use very little hot water most days so I'm wondering whether, instead of using the night rate to heat the whole cylinder, I should just use the boost for 30 mins each morning. Do I need to run tests with meter readings or is the answer obvious (to some)?

So 30 minutes peak will cost about the same as 60 minutes off peak.

30 minutes boost will only give you a small amount of hot water (which will probably be cold by the evening even if you don't use it)

If you really do only use a small amount of hot water, 60 minutes a night should be more than enough to keep the tank topped up for the whole day if properly insulated.

(And if 60 minutes is more than enough, it will of course thermostatically cut out before the 60 minutes has elapsed )

Edit: According to this thread you posted a couple of months back, you don't have E7.
https://forums.moneysavingexpert.com/discussion/5168528

You should speak to your supplier to establish exactly what you are charged, for what and when.

RebTech

molerat wrote: »

Boost for 30 mins in the morning during off peak - on E7 all units used in off peak times are charged at the lower rate. You obviously need to know when your off peak times are and confirm your meter switches at the correct times including the BST/GMT difference. Usually fairly simple to fit a timer to the boost.
https://customerservices.npower.com/app/answers/detail/a_id/179/~/what-are-the-economy-7-peak-and-off-peak-periods%3F

To "Boost for 30 mins in the morning during off peak" would be ideal but my off peak times according to that page (and others) are "7 hours between 10pm and 8.30am" so how would I know? Sit in the cupboard with a torch all night?

RebTech

footyguy wrote: »

If you really do only use a small amount of hot water, 60 minutes a night should be more than enough to keep the tank topped up for the whole day if properly insulated.

That sounds sensible except how would I time it?

You should speak to your supplier to establish exactly what you are charged, for what and when.

If only! That thread is an old one, I have another current one describing my issues with Scottish Power (which seem to be due to their issues with IT).

molerat

RebTech wrote: »

To "Boost for 30 mins in the morning during off peak" would be ideal but my off peak times according to that page (and others) are "7 hours between 10pm and 8.30am" so how would I know? Sit in the cupboard with a torch all night?

Pretty much

enjoyyourshoes

Thanks for the title of your post


It reminded me to review the heating and hot water timer !


Which I have now completed and save a few hours a week roaring away.


So thanks again Reb Tech !

RebTech

I'm glad somebody's gotten something out of it.

RebTech

Having done some experimenting and studied the consumer unit it looks like the water heating boost and the non-storage room panel heaters are permanently connected to the low-rate meter -- with the main water heater and storage room heaters of course.

It's the low rate meter that turns when the boost and panel heaters are on, regardless of the time of day. Looking at the grouping of circuits within the consumer unit, it seems only the storage and main water heaters are time-controlled. So there's three types of circuit, "normal" (high rate) ones (cooker, sockets, lighting), and both time controlled and non-time-controlled low rate circuits.

Anybody recognise and can tell me anything about this setup? In particular, assuming it's not E7, what's it called?

molerat

One of the ones in here probably http://www.scottishpower.co.uk/energy-efficiency/energy-efficiency-at-home/electric-heating/
:eek:

This is only going to add to the problems in your other thread making a change of supplier almost impossible, it looks like footguy already picked up on this point :eek:

RebTech

molerat wrote: »

One of the ones in here probably http://www.scottishpower.co.uk/energy-efficiency/energy-efficiency-at-home/electric-heating/
:eek:

This is only going to add to the problems in your other thread making a change of supplier almost impossible, it looks like footguy already picked up on this point :eek:

Thanks for that link, looks like it might be Comfortplus Control.

Normal domestic appliance usage will be recorded on the Domestic meter.
Heating and hot water usage will be recorded on the Control rate meter.
Storage heating should form 60% of the total installed heating load. The charge provided by ScottishPower depends on the forecast temperature as Weathercall is an integral part of the tariff. The actual charge period is therefore weather dependant as described above.