Originally Posted by malconium
I don't actually have to switch between potable and heating water......So a 3 way valve is not needed.
Ah, but it is. You need to get a pencil and paper and draw this out.
Normal operation takes the water from the freshwater tank, to the pump, then splits to feed the water heater and cold water systems.
Your system is doing nothing more than recirculating water.
How are going to get water to the cold taps if you don't draw it from the tank? The only way to do that and recirculate hot water with the same pump is a 3 way valve.