timer for economy 7 immersion heater?

[pretzelz]

Hi all,

In a bedroom upstairs, there is plasterboard house the immersion heater. There is a switch on the wall to turn it on or off.

Usually I stay up till 11:30pm when the economy 7 night rate kicks in, when I want to turn the heater on, and I turn it off in the morning when I wake up.

I want a digital timer just to turn it on for a few hours each night after 11:30pm. There are timers on Ebay for about £15+ but:

* Would this simply replace the manual switch on the wall?
* Would my heater be 3kw? All the timers seem to be 3kw
* There are some £75+ timers for economy 7. Why the price hike? I just need it turned on late night, what else fancy would justify this price? Must I have an official economy 7 timer?

Many thanks for your advice!

 

[Steve]

How is the immersion supplied? If you wanted to turn off its circuit, how would you do this? Are there two immersions in the cylinder? One at the top and one lower down?

Usually where there is only electric heating in a house, there is a second fuse box and everything on this becomes live when eco7 turns on - there is a second port on the metering equipment which turns on at eco7 time.

You shouldnt have to turn it on or use a timer if it is correctly set up.

An eco7 immersion should come on at around midnight, then run on a thermostat for 7 hours, and go off. It wont actually run constantly for 7 hours, as its thermostat will stop it from boiling the water, and if the cylinder is well insulated, it might only run for a couple of hours and not have to come back on.

 

[pretzelz]

Thanks for your advice Steve. All I know is this: In the bedroom is a switch, similar to a light switch size, but there's a little box behind it. When I turn it on, the water-heater (not central heating, electric only in the house) turns on. When it has reached boiling point (usually piercingly hot!) it stops. Then it just maintains that temperature continually until it is turned off by the switch. I've never noticed any alternative modes. It could possibly be the original immersion heater built with the house from the 80's! (An x-mod system built house).

That's why I figured, rather than me turning it manually on and off to coincide with the cheaper rate times, get a timer to do it.

 

[crystal ball]

Usually where there is only electric heating in a house, there is a second fuse box and everything on this becomes live when eco7 turns on - there is a second port on the metering equipment which turns on at eco7 time.

You shouldnt have to turn it on or use a timer if it is correctly set up.

.

Only if the immersion is wired from the off peak board, which is not the case

Yes you can have a timer, best to leave the switch in circuit and wire the timer downstream of it, most immersions are 3 Kw, no you do not need an "economy 7" timer

 

[pretzelz]

I didn't realise appliances needed separate wiring... if the immersion isn't wired to the "off peak" board, then nothing in the house is? So why do I even have economy 7?

The power company said to me previously, between 11:30pm-6:30pm you're charged at 6.5p per KWH, and the rest of the time at 22p. (Not those exact figures but similar). Why do things need to be more complicated with alternative wiring etc?

I know the electric meter outside the house has two readings, which I have to submit each time.

 

[crystal ball]

When the meter switches over to E7 the whole house is on cheap rate so anything you use - dishwasher, tumble drier, immersion heater will be on that rate.

The off peak board is energised at the same time to charge up the storage heaters

 

[pretzelz]

ah, its not night storage heaters, it just a water heater.

But basically yes, I can buy a simple timer switch, this will turn the water heater on for a few hours each night, when the electricity is charged for the whole house at a cheaper rate?

Many thanks

 

[Steve]

How do you heat the house?

 

[pretzelz]

manual convection heaters. We try to limit use of these just to the evenings.

So just to confirm, I can buy a standard timer switch? Not an econ7 timer switch?

Thanks

 

[crystal ball]

Yes you can as long as its rated for 3Kw

 

[ban-all-sheds]

If you are on Economy 7 and don't have NSH you should look closely at how much day rate electricity you use - you may be worse off with that tariff.

 

[Steve]

Storage heaters would work out a lot cheaper to run, since they use no electricity at peak times. While the sparky's fitting them see if he can look at fitting an off peak element into the cylinder too.

 

[Wontdothatagain]

If you are on Economy 7 and don't have NSH you should look closely at how much day rate electricity you use - you may be worse off with that tariff.

Generaly speaking he will be paying a lot over the top unless the OP works night shift.

 

[pretzelz]

Well, when it was just me living on my own in the house, by peak winter time (south UK) it was £40 a month. There are now 4 of us, the bill is about £160 a month in electric. No gas. ...Not sure how much the others use the heaters at night, but I'm guessing at least a few hours each evening. If we all try to use our heaters minimally, perhaps it would cost the same or less than using night storage heaters for many hours I wonder...


I'm still confused about whether eco7 has seperate wiring to certain appliances? Or whether the whole house is served with cheaper electricity to any plug socket between the alloted time. I've never noticed any difference with wiring etc.

 

[tomssi]

I know it is an old thread, but just wondered how you got on with this. Did you fit a timer and if so which one?

The reason I ask is that I have been looking into the same scenario for myself and nobody mentioned that during day / peak time there will be no electricity to this spur, so how would the timer keep its time settings?