Bert, Chain downpipes were never a big success as the water leaves the chain when wind blows. The water then splahes around the sump and makes a big mess. The last customer who ignored my advice finished up with mud and water stains over a white brick wall. But I digress so back to your question. Put a round tapered nozzle in the gutter, hang the chain on a rod put across the nozzle, make sure the chain is in the center of the nozzle, and directly over the centre of the sump. The tapered nozzle will direct the water onto the chain. Whether the water stays on the chain is in Gods hands.
