Economy 7 Electric AGA
The first electric AGA was the Economy 7 model, launched in the mid-1980s (also known as the '30amp' or 'Night Storage' AGA).
Important Note:
The Economy 7 AGA has been discontinued as of 31st May 2018.
It's a 'Traditional' model of AGA - on at full heat all the time - and if that's what you need then it's great: constant warmth and cheap to run (it 'charges' using low-cost overnight electricty on the Economy 7 tariff).
However, it can't be programmed to lower its temperature like the AGA Total Control and in modern well-insulated houses that's a better solution (proper AGA cooking with lower heat-output and lower running costs).
It means that there's less demand for 'Traditional' (on at full heat all day) AGAs and we're at the point where it's no longer economic for the factory to keep making the Economy 7 version.
If you have one though, don't worry - you're not alone and spares will continue to be available for many years to come.
The Original Electric AGA
The classic AGA heat storage cooker - The Economy 7 electric model is ideally suited where a constant background heat is needed to warm the room as well as provide the cooking facilities.
It is cheap to run (a little bit less than an oil one, and with lower maintenance costs) and works well. Not needing a chimney or flue helps as it can be installed in more varied locations than the oil one (which is tied to a chimney/flue).
It works very much like a night storage heater - charging a bank of heat-storage bricks in the overnight cheap-rate period of the Economy 7 tariff, then using a small heat transfer fan to distribute the heat to the cast iron ovens and hot plates throughout the day.
Available as a two or four oven model, it's designed to be fully up to temperature all day - cooking beautifully and warming the room at the same time.
It's still the cheapest electric AGA to run but other models may be more suited to properties that don't need as much warmth in to the room.
Originally known as 'The Electric AGA' (it was the only one fuelled by electric after all, so this made perfect sense!), it is often now referred to as 'The 30amp' or 'Night Storage Electric AGA' to distinguish it from the other electric models.
How it works
The Economy 7 Electric AGA has a bank of heat storage bricks that 'charge up' in the cheap-rate Economy 7 period overnight (reaching temperatures of up to 725 degrees Celsius), this heat is then transferred across to the hot plates and ovens when needed during the day. As the 'core' of heat storage bricks is charged overnight in a shorter time period this means a higher powered connection (a standard 32amp cooker circuit) is required.
Highly efficient insulation retains the heat inside the cooker so it isn't too hot to touch (surface temperatures are much the same as all other AGAs) and there's easily enough heat to last for a full day's cooking. If the heat store does get low and it's still peak rate time the cooker will detect this and boost itself (only to a lower level though) until the cheap rate starts and it can fully charge up again.
The ovens are ventilated to outside using exactly the same system (28mm copper pipe and external fan box) as the 13amp electric AGA.
The economy 7 electric AGA is available as a two or four oven model (not three oven unfortunately), in all the AGA colours (except Claret) and can be fitted with the optional electric module. (The economy 7 has a slightly different front plate so isn't available as a Classic Special Edition but you can fit colour matched cast iron lids if you wish.)
The economy 7 electric AGA isn't available with AIMS.
Running costs are the cheapest of any AGA. This is because the power is used during the cheap-rate overnight period when electricity is generally half price or less.
Easy To Position
Because it's electric there's no need for a flue or chimney, after all there are no gas or oil fumes to get rid of. (It still has a small 28mm oven ventilation pipe to outside because, just like all traditional AGAs, the cast iron ovens vent to outside.) This means greater flexibility as to where in your kitchen you want your AGA to be.
The Economy 7 Tariff
Economy 7 is available everywhere in the UK and to get it, it's normally just a case of ringing your electrictiy supplier and requesting a change of tariff. They'll then arrange to come and fit you a new 'dual rate' electric meter. (Domestic users don't usually get charged for this.)
The new meter has a 'radio teleswitch' built in - this receives a radio signal to let it know when to count on the cheap 'night' rate (normally midnight to 7am GMT) and when to count on the normal 'day' rate.
You don't notice when the day/night rate switch over happens (there's no interruption in the electric supply), you just get your 7 hours of cheap electricity every night.
Typical prices compared to a standard '24-hour' tariff are fractionally higher during the day and around half-price overnight, so as long as the greater proportion of your usage is overnight you'll be better off on Economy 7.
(You can also switch to using your washing machine, tumble dryer, hot water immersion heater and dishwasher overnight too to maximise savings.)
Wiring Requirements
TWO circuits are required:
Circuit 1 - Main Power Supply
A standard 32amp cooker circuit (an existing one can usually be re-used or adapted).
Circuit 2 - 'Economy 7 Signal'
This is the clever part: a second 'signal' circuit.
An economy 7 meter has a second set of terminals that only come on during the cheap rate period (overnight); the AGA's second circuit is wired from these (via a consumer unit and the appropriate switch).
Since this is only ever on during the cheap-rate time, the AGA knows that it's ok to 'charge' its heat-store during this time.
A Couple of Things to Note
1. Have the wiring done BEFORE the electric suppliers come to change the meter.
The extra wiring (for the AGA's 'signal circuit') needs a pair of wires (known as 'tails') connecting to the separate terminals in the meter - your electrician isn't allowed to do this (only the 'meter people' can).
So ask your electrician to have the cables ready so they can be connected when the new meter is fitted.
2. If it's too much work to install the 'signal' circuit
It is possible to use a time-switch to mimic it instead - this is cheaper to install however it's important to make sure the time-switch is always in sync with the 'real' Economy 7 period (check regularly!) If not you could use some 'peak' electricity to charge the AGA each day which might add up over time if it's not kept in check.