Speaking of water heaters

[cleaning up mud]

My boilers have at least 1.5 inch inlets, the tankless heaters only have 3/4, all my copper plumbing is 1 inch. Does it seem to work ok?

 

[dogwasher]

Are you asking if the 3/4 will handle the volume? Each Tankless only handles so many gallons per minute, you will need to turn the 1" onto a manifold and pipe into two or three tankless heaters depending on the demand.