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We answer your gas, electricity and energy efficiency questions

The Energy Doctor- Energy saving FAQs

Hundreds of you emailed your questions about energy savings to our "energy doctor", and we've got the top questions and answers right here.

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Q. Is it true it costs more to switch lights off and then on again, than it does just to leave them switched on?

A. It's a myth that it costs more to switch your lights on and off than to leave them on.

Old-fashioned incandescent bulbs - the kind with a filament in them - don't draw any more power than normal when they're first turned on. If a bulb says 60W on it, it will draw 60W of power from the instant it's switched on.

With energy-saving bulbs, it's again cheaper to switch lights off when you leave a room than to leave them switched on.

While low energy bulbs do draw more power in the first few minutes of being switched on than they do when they are running normally, the energy used by them starting up is only the equivalent of leaving them running for a few minutes.

Q. Is it cheaper to leave the central heating on at a low temperature rather than switch it on and off as needed?

A. It's a common misconception that it's cheaper to leave your heating on all the time.

Boilers use more power initially to heat radiators from cold. However, the cost of doing this is greatly exceeded by the cost of keeping the boiler running all of the time — even if you set the temperature of the central heating down low.

You should set your heating to come on shortly before you are going to need it (for example, before you get up in the morning or before you come in from work) and to go off again at a time when you leave the house.

Q. Are there energy-saving light bulbs which don't take ages to reach their full brightness?

A. Some energy-saving bulbs can take a little longer than normal bulbs to reach full brightness. This is a result of the technology they use, which is also what makes them so much more efficient than traditional incandescent bulbs.

Many modern energy-saving bulbs take little more than a few seconds to warm up to full brightness. You should look for the Energy Saving Recommended label when choosing your energy-saving bulbs, as these have to pass certain criteria on maximum warm-up time.

You can also get energy-saving bulbs which are designed to be fast-start bulbs, meaning that they do not have a warm-up period. Look for bulbs labelled 'fast-start' or 'quick-start' when you are buying new ones.

Q. What are the minimum energy efficiency standards that landlords of residential properties are legally required to fullfill?

A. As of April 2018, landlords in the private sector are required to maintain an EPC rating of E or better.

This means that energy efficiency improvements for rental properties with a rating of F or G are compulsory for landlords.

Improvements that can be required include:

Q. Will I save money by turning radiators off in individual rooms?

A. You will almost certainly be able to save money by turning your radiators off in individual rooms that are not in use. It's a waste of money and energy to be heating unused spaces.

Also, close the doors to any unheated rooms to help stop the warm air from the heated rooms or spaces escaping into the colder ones.

If you have gas central heating, the one room where you should not turn off, or turn down, a radiator is the room where your thermostat is fitted. This is because it can interfere with the temperature regulation of the central heating.

Q. Is it better to just use the gas fire in my living room to keep my house warm or to heat up the whole house with the gas central heating?

A. Gas central heating is usually more efficient at providing heating compared with a gas fire. Central heating is able to produce more heat per unit of gas used, as much of the heat produced by living-flame gas fires may escape up the chimney.

Which works out more cheaply for you will probably depend on how many rooms you have or want to heat, and whether you can control the individual radiators in the different parts of your house.

If you cannot turn off or turn down the radiators in the other rooms in your house, you will be better off using your gas fire, as by using the central heating you will be wasting money heating unused rooms.

Q. What's the most effective way of heating my all-glass conservatory?

A. The first thing to consider is whether your conservatory has double- or triple-glazed glass, or whether it's single-glazed. If it's single-glazed, it may be difficult to keep it heated to a comfortable level in cold weather. In this case, you could use heaters such as halogen heaters or fan heaters.

If you have double or triple glazing, then the conservatory will be better at holding in heat. In this case you can consider fitting a radiator of the type you have in the rest of your house.

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Beat the energy price rises

All of the big six suppliers have raised their prices in 2019 following the Ofgem price cap increase. Don’t get caught out - switch to a fixed deal today!