- Setting the programme controller and switching on the machine activates the door interlock: once the door is shut, it cannot be opened until the programme is finished.
- As soon as the door is locked, the programme begins. The inlet valves are opened, allowing water to flow into the drum. On the way, it passes through the detergent tray, collecting powder or liquid.
- The water entering the drum compresses air in a pressure chamber. This pressure is relayed along a flexible pressure tube to a pressure switch, which shuts the inlet valves at the programmed water level.
- The heating element comes on, raising the water temperature to the programmed level. On very hot washes, only the hot inlet valve may open. This reduces the time the heating element is on.
- The motor is started, driving the drum at around 55rpm. This is the best speed for washing clothes: they stick to the drum until the top of a revolution, then fall back into the detergent solution.
- The motor is switched off and the pump turned on to empty dirty water from the tub via a lint filter and the drain hose. After a hot wash, the cold inlet valve may open first to cool fabrics gradually and protect them from damage.
- The pump is switched off and the cold valve opens to start the rinse cycle. A repeated sequence begins: the tub filling to the programmed level, the drum revolving and the water being pumped out.
- At the end of the final rinse the spin cycle starts. The motor is switched on, revolving the drum at high speed. At the same time the pump is switched on to remove the water coming out of the clothes.
- The motor is switched off. After a delay to allow the drum to stop spinning, the door lock is disengaged. The programme is now finished and the door can be opened.
- The washing and drying programmes are set using the programme selector knob. Extra positions on the knob allow the choice of high or low drying temperature settings.
- The washing mechanism works in exactly the same way as in a front loading washing machine.
- Once the clothes have been washed and spun, the machine switches into drying mode. A fan draws cold air over heating elements and passes the dry heated air into the drum. The clothes are turned in the drum and moisture evaporates.
- The warm wet air then passes into a condenser unit. Here, the air comes into contact with, and is cooled by, a series of cooling fins over which cold water from the water supply trickles. As cooler air can hold less moisture than hot air, the excess is deposited onto the cold surface, drips down and is pumped out through the same drain pipe as the water from the wash.
How the programmer works
The programmer is the brain of your washing machine: once you choose the desired setting for the types of fabrics in the wash load, the programmer takes over. Every programme is a permutation of the same factors:
- The amount of water taken in via the inlet valves (which dictates how far the clothes fall when they drop off the top of the drum - and so how hard they hit the water)
- The temperature of the water and detergent solution
- How long the drum turns for during the wash and spin sequences; and
- How fast the drum turns
The programmer also controls the operation of the pump to drain the machine at various points in the wash cycle.