Tankless problem?

[drod309]

I currently have an electric water heater inside my home under a stairwell. I am converting to a natural gas tankless water heater. The hot/cold lines coming into my current water heater are 1/2" pvc. The tankless must have 3/4" pvc going into it. The plumber that came out said that he can run the existing lines from under my stairs, thru the drywall and outside leading to where the tankless heater will be. Being that my current lines are 1/2" and the tankless requires 3/4" is that a problem? Is that a fairly easy thing to do? I just dont want to see any hidden costs later. The plumber never mentioned anything about the 1/2" or the 3/4" I just happened to be reading up on the tankless water heater.

 

[havasu]

I personally would call the TWH manufacturer and ask them. Less volume (1/2" vs. 3/4") may be a concern which could only be confirmed through the specific TWH company.