How to use Economy 7 cost efficiently!?

tim_p

Yes, that switch looks to be controlling the ‘boost’ immersion.  You could probably check by leaving it off (as it should be) then this evening turn it on again and you should hear the immersion heater sing / hiss and if someone else watches the meter it should start flashing or spinning rapidly. 

Gerry1

Turn both immersion heaters off via the switches on the wall.  Let the water get really cool, then turn on the lower heater during the day (follow the wiring to the switch).  Check that the meter shows day rate, then turn on the lower heater.  Make sure the water is still cool after half an hour.  That has checked that the lower heater can't top up in the day at expensive rates.

Then turn on the upper heater for half an hour and then leave it switched off.  You should now have hot water; this has checked that the upper heater is on a 24h supply.

As a reminder and as a courtesy to the next occupant, you may wish to add a notice next to the switch, e.g.

WARNING

Leave permanently OFF, except in an emergency to get half a tank of EXPENSIVE hot water

before the cheap overnight rate starts.

jl1996

tim_p said:

Yes, that switch looks to be controlling the ‘boost’ immersion.  You could probably check by leaving it off (as it should be) then this evening turn it on again and you should hear the immersion heater sing / hiss and if someone else watches the meter it should start flashing or spinning rapidly. 

Awesome - thank you so much!!

jl1996

Gerry1 said:

Turn both immersion heaters off via the switches on the wall.  Let the water get really cool, then turn on the lower heater during the day (follow the wiring to the switch).  Check that the meter shows day rate, then turn on the lower heater.  Make sure the water is still cool after half an hour.  That has checked that the lower heater can't top up in the day at expensive rates.

Then turn on the upper heater for half an hour and then leave it switched off.  You should now have hot water; this has checked that the upper heater is on a 24h supply.

As a reminder and as a courtesy to the next occupant, you may wish to add a notice next to the switch, e.g.

WARNING

Leave permanently OFF, except in an emergency to get half a tank of EXPENSIVE hot water

before the cheap overnight rate starts.

That's great, very helpful - thank you so much!

jl1996

I turned my water off completely last night to run a test and my storage heaters used up quite a bit of electricity over night - I only have two on at the moment and they are both set to input at 2 and output at the very lowest. I am unable to find the meter readings, as in the electricity cupboard (where I plug the key in) doesn't show anything which indicates meter readings (only a switchboard for the mains). I think I may need to contact my supplier or landlord for help with that. 

RE the immersion heater, there is only one switch on the wall and then there is the box outside which is the Horstmann Electronic 7 timer. So am I right in thinking to switch it off at the wall and keep it switched on on the box? 

jl1996

Thank you for all of your help! 

Gerry1

jl1996 said:

RE the immersion heater, there is only one switch on the wall and then there is the box outside which is the Horstmann Electronic 7 timer. So am I right in thinking to switch it off at the wall and keep it switched on on the box? 

That suggests that it's a cheapskate set up, i.e. the immersion heater has only one 24h supply rather than an overnight supply switched by the meter for the lower heater and a 24h supply for the boost heater.

It means that the Horstmann timer is 'shadowing' the cheap rate times set by the meter.  That's fine if they're exactly the same, but if they get out of kilter then you'll get massive bills.  The Horstmann should be left on the Timed setting.

So tonight's homework is to find out exactly when the meter switches over to cheap rate and to make sure that the Horstmann timer switches at exactly the same time.

Beware that in some areas there's a gap of two hours in the middle of the night, e.g. cheap rate may be 2230 - 0030 and 0230 to 0730.  Hopefully the Horstmann has battery backup; if not it's a formula for bankruptcy if it drifts because of power cuts (e.g. cheap motorised timers).

jl1996

Gerry1 said:

jl1996 said:

RE the immersion heater, there is only one switch on the wall and then there is the box outside which is the Horstmann Electronic 7 timer. So am I right in thinking to switch it off at the wall and keep it switched on on the box? 

That suggests that it's a cheapskate set up, i.e. the immersion heater has only one 24h supply rather than an overnight supply switched by the meter for the lower heater and a 24h supply for the boost heater.

It means that the Horstmann timer is 'shadowing' the cheap rate times set by the meter.  That's fine if they're exactly the same, but if they get out of kilter then you'll get massive bills.  The Horstmann should be left on the Timed setting.

So tonight's homework is to find out exactly when the meter switches over to cheap rate and to make sure that the Horstmann timer switches at exactly the same time.

Beware that in some areas there's a gap of two hours in the middle of the night, e.g. cheap rate may be 2230 - 0030 and 0230 to 0730.  Hopefully the Horstmann has battery backup; if not it's a formula for bankruptcy if it drifts because of power cuts (e.g. cheap motorised timers).

Awesome thanks - I will look into this!

pokora

You should check with your supplier, which hours are E7 in your postcode.
Also I think I read something about plug a key, do you have a prepayment meter ? Could you upload a picture also please ?
I have also a Horstmann 7 timer but manual.