Control of your electric heating

Where electric heating has been supplied it will normally be a system using electric storage heaters, the objective of night storage heaters is to utilise the cheaper electricity available during the night. This ‘off-peak’ tariff is usually called ‘Economy Seven’ (E7) it is available for seven hours overnight (usually midnight to 7am) and costs about 4p per unit. If you do not have an E7 tariff you can request it from your electricity provider who should change it for you for free. You will have two meters or one meter with two or more readings. One of the readings (or meters) measures the ‘on-peak’ daytime electricity and the other measures the night-time ‘off-peak’ electricity.

Night storage heaters

Night storage heaters are insulated boxes containing bricks with electrical elements running between them. Storage heaters charge up using the cheaper (night) rate electricity. You can set the ‘charging’ controls to fill the box with the desired amount of heat, for example, setting it on 4 (out of 6) means the elements will shut off when the box is 2/3 full. The storage heaters are covered with insulation. This holds most of the heat in the box for up to 14 hours or so but this heat will eventually ‘leak’ out. At the top of the box is a flap, which can be opened to let the heat out more quickly. The more the flap is opened, the faster heat can escape and heat the room.

Operating night storage heaters

Controls vary depending upon the type of heater installed. Older heaters may need to be set manually at night and then manually opened when heat was needed. Newer models have thermostatic controls, which allow a specific storage and output temperature to be set. Both of these types can have a built-in fan, which blows heat out of the heater rather than just let it drift out as convected heat.

There are usually two main controls on a night storage heater; input control and output or boost control:

Input control: This determines how much heat is ‘charged’ into the storage heater during the night and should be kept on a low setting during mild weather when only a small amount of heat needs to be stored. On older models this is determined directly by the ‘Charge’ control setting. On more recent models ‘charging’ is thermostatically controlled usually by room temperature.

Output control: This is sometimes called ‘boost’ or ‘room temperature’. As described above, night storage heaters have flaps, which open to release heat. How much the flap opens is determined on older models directly by the output control. On more recent models the flap is controlled by a thermostat. You set the thermostat by adjusting the setting of the ‘Output’ control. The boost control is usually numbered 1-5. The heater will operate quite well with the setting at number 1. If however, you need extra heat during the afternoon and evening turning the boost to numbers 2-5 will increase the heater output. Remember to re-set to 1 before you go to bed. This may sometimes explain why storage heaters run out of heat during the afternoon.

Tips if you have older storage heaters:

  • Remember to turn down the ‘output’ control before you go to bed to stop heat being given out when you don’t want it
  • If the room is cold, turn up the ‘output’ control until it warms up
  • As the weather gets warmer turn down the ‘input’ control to store less heat
  • When the room is warm, turn down the ‘output’ control to save heat for later in the day

Tips for all storage heaters:

  • Block-up any open chimneys or do not install a storage radiator in rooms where an open fireplace is present (including gas flame-effect fires)

Panel heaters

Panel heaters use direct acting energy, which means they provide fairly instant heat once switched on. They are usually compact in size, wall mounted and are often used for areas which only require heating for short periods of the day, like bedrooms, however they can be used as a whole house heating system.

Panel heaters offer different features such as 24 hour timers for improved efficiency. Selected models can also be linked to a central programmer for maximum control.

Because on-peak electrical heating is expensive (normally about 10 to 15p per unit) electrical panel or convector heaters are not recommend, except as complementary heating.

Hot water

Hot water should be supplied from a high capacity storage cylinder. The cylinder, with its tank above, is insulated and fitted with immersion heaters.

If you have a hot water storage cylinder, it will usually be fitted with a cylinder thermostat to control the hot water temperature (this should be visible on the outside of the cylinder). It switches the heat supply from the boiler on and off as necessary to keep the water at a set temperature. The temperature you select will determine the temperature of the hot water coming out of the hot water taps. Ideally, it should be set to 60°C (140°F). (Certainly not lower than 55°C as this could cause legionnaires disease.)

For water that is heated by an electric immersion, the thermostat will be inside the tank. If you heat your water with a combination (combi) boiler, the heating control for your water is on the boiler.

TIP: If you tank is not insulated, fit a BS Kite-marked insulating jacket, 75mm or 3 inches thick, around your hot water tank. It will save you around £40 a year - and as it will only cost around £12 to buy, will pay for itself in well under a year.

There are two basic ways of using the hot water system, the choice is yours and will depend upon your lifestyle and water usage;

Using the night storage facility

If you have a sizeable demand for hot water for cooking and washing, then this is the preferred and most economical method. Using the immersion heater at the bottom of the cylinder, a full tank of water is heated at the cheap night rate. The hot water is then drawn off as required during the day. The top immersion heater can then be used to "boost" the water temperature if required during the afternoon or evening.

Alternative methods

If you do not use large quantities of hot water it may be cheaper, especially if you stay up late or rise early, to dispense with the "night storage" facility. Using the top immersion only as required, you may still obtain much of your hot water on the cheap night rate and avoid the heat losses inherent in storing quantities of hot water. The degree of economy you obtain will depend on you timing your water use to avoid the more expensive day rate electricity supply.

Points to remember

Day rates of electricity can be more than three times as expensive as night rates. Check the actual charge with your electricity provider, this will normally be shown on the bill.

Don’t be tempted to use alternative electric heating appliances. These are all operated on day rate electricity and most have no effective temperature control.