If your washing machine door seal has a build up of mildew or black mould it is caused by a bacterial build up, often by incorrect usage of detergents. front load washer door prop

Most likely reason for this is usage of liquid or gel detergents which have no bleaching additives in them, these bleaches are important for helping to kill the bacteria that will grow inside the seal and other parts of the washing machine.

The reason detergent manufacturers add bleach to wash detergents is primarily to ''brighten'' clothes and prevent whites from greying.The problem of mildew and mould on doorseals is a fairly modern one as before the advent of liquid detergent the staining on door seals wasnt a problem.

Under dosing of detergents is another cause and if continued bacterial growth will take hold

Another big factor is the use of low temperature wash loads that modern fabrics have to be washed at, bacteria wont be killed on a 30 or 40 degree wash cycle and will continue to multiply in the door seal unless killed

So now we know what causes the unsightly mildew or mould on door seals, how can we rectify it?

If the mildew isn't too bad a cloth and some bleach may remove it or possibly make it less unsightly, but the only real solution is replacement of the door seal. Most domestic appliance engineers charge around £50-80 depending on make and model.

After the door seal has been cleaned or replaced the following should be done to prevent it happening again.

Use powder detergents in conjunction with liquid or gel detergents
A Monthly "'service wash" should be carried out. This is a 95 degree wash with nothing in the drum this will kill the bacterial build up
Wipe dry the lip of the door seal when finished wash cycle.
Leave door ajar when not in use.
Avoid "'alternative"' wash products such as wash nuts, ecoballs etc
Quite often this problem of unsightly door seals goes hand in hand with a washing machine that has a bad smell.

This smell which can be likened to a fusty, musty smell, is again the bacterial build up inside the washing machine but it may be a lot harder to completely remove the smell. Multiple boil washes may be enough to kill enough of the bacterial build up, but quite often a specailist additive such as affresh may be required.