I have a boiler with a tankless coil that uses 1/2" pipe. Currently, the cold water supply line is 3/4" until about 10 feet from the coil, where it drops to half inch. The hot water piping coming off the coil and feeding every hot water sink and shower in the house is 1/2". I'm wondering if I should replace the supply and return piping with 3/4", or if there's so little added benefit likely to accrue from upsizing to 3/4" due to the 1/2" coil in the middle that I should focus on other likely causes of my problems with low pressure at the tap? Has anyone ever set up a 1/2" tankless coil with 3/4" supply and return? Is it worth doing?