Hi, I have a shower coming from a bath mixer tap. Because the hot water is such low pressure I fitted a pump to the hot wter tank - this works fine. The problem is, the pressure of the hot water far outweighs that of the cold and if you shower for anything longer than few minutes the hot pushes the cold back up the pipe, fills the tank and water starts shooting out the side of the house! I am waiting for a quote for a plumber to fit a pump that will work for hot and cold thus equalising the pressures but I was just wondering, is there a fitting that will stop the cold water reversing as this would be much cheaper than a new pump? I have googled this but am confused as some say they are for air only and I am not sure about sizes. Any advice would be great. Thanks in advance. Happy Easter to all!