Do you currently have hot water?
If NO (show empathy and provide further reassurance we can help)
If YES - why are you considering replacing?
Acknowledge reason and use when building rapport.
(ie. they mention it's due to insufficient hot water, say something like- we originally had a 40Gal tank in our home, I noticed it wasn't keeping up with my family's needs, so we upgraded to a 50Gal.
We're now able to run the shower and laundry without worrying about running out of hot water).