Energy Efficiency

Washing up by hand can be an inefficient process, especially when you consider a dishwasher can deal with a single dinner party-sized load using less than 17 litres of water, whereas it can take 20 litres of water to fill a single sink. Dishwashers also clean to a higher standard, as the water reaches hotter temperatures than hands can tolerate. To reach these temperatures, a dishwasher uses approx 1.5kW of energy per cycle, yet a hot water system uses 2.5kW to heat the water to fill a sink.

Check the energy ratings of the appliance before you buy. The letters refer to energy efficiency, washing performance and drying performance, with AAA-rated models the best. For energy costs, allow 11p per cycle, before detergents.

To economise, wait until the dishwasher is full before running a cycle, and don't rely on half-load settings – they save less than 25% of the energy and water used to run a full load.

Detergents

To get sparkling results, dishwashers use a combination of detergent (to clean the crockery), salt (to combat water hardness), and rinse aid (to eliminate watermarks). All dishwashers have an indicator light or other reminder to let you know when the salt or rinse-aid reservoirs need topping up, but if this is too much effort, why not try three-in-one tablets, which provide salt, detergent and rinse aid in one dose?

Some machines now have programmes to optimise results using three-in-one tablets, or you can use the tablets and still fill up the salt and rinse-aid reservoirs, too.