LG Washing Machine does not drain?

Having moved house we cannot get our LG 1243F(H) to drain properly. We have cleaned the filter and knocked out a large amount of muck from the drain hose. If we set it to spin only - no problem. However, it is clearly not draining properly during a full cycle as there is a large amount of soap suds left. We have tried both connected to the U bend direct and by hooking the drain hose over the sink edge. It appears to work but flashes 'no drain' at the end of the cycle and leaves clothes wet unless we initiate a spin.