Lg front loader, water not draining, so rinse cycle cannot start?

It does the wash load but it does not empty the water so the rinse cycle can begin. Have tried emptying the drain down the left hand side (03 error shows and door won't unlock) and cleaning out the filter but still no luck. It makes a sort of buzzing sound when it should be draining. Help anyone out there. Can't afford a new one and cost of repair is almost the same as buying a new one.