In the process of a large home remodel. Starting to re-plumb the master bedroom side converting most of the existing copper to PEX-A. Once I got into walls and traced copper lines I'm concerned about flow/pressure issues and hoping for advice. Currently in the master bath there is a 3/4 cold supply coming up through the slab that acted as the supply for the cold side of the master tub, shower, 2 vanity sinks and a hose bib. It continued on to supply the cold water input to 2 40 gallon hot water heaters in parallel in the attic that then fed the hot side of the master tub, shower, 2 vanity sinks, and the hot side of another tub/shower and vanity. So the single 3/4 line coming through slab was feeding at least 11 outputs.
My plan was to replace the 2 hot water heaters with a single tankless and trying to determine if I need to try and find another main line to feed it from? Or should I not worry about it and will the single 3/4 line be sufficient to run a large master shower (2 heads) as well as a second shower at same time? I dont have the GPM ratings of faucets or shower heads yet, and dont have water pressure readings, so just looking for general advice or am I overthinking possible issue of overrunning the 3/4 line capacity?
My plan was to replace the 2 hot water heaters with a single tankless and trying to determine if I need to try and find another main line to feed it from? Or should I not worry about it and will the single 3/4 line be sufficient to run a large master shower (2 heads) as well as a second shower at same time? I dont have the GPM ratings of faucets or shower heads yet, and dont have water pressure readings, so just looking for general advice or am I overthinking possible issue of overrunning the 3/4 line capacity?