I'm fitting a gravity feed shower and I've bought a pump to go with it. The instructions with the pump say that it's best to fit it as close to the bottom of the hot water tank as possible. I'm running the plumbing for the shower through the loft and down into the bathroom. If I fit the pump next to the tank, which is in a bedroom cupboard, it means the water will be running down into the pump from the hot water tank and the cold tank, which is in the loft, then back up to the loft from the pump. That doesn't seem to make sense to me. Is that normal?