so you have a regular gas hot water tank, how many BTUs is it. they
vary from under 30 thousand to over 75 thousand BTUs. larger 75 gallon
tank with 75K BTU costs a bit more but is money well spent

while some crow about tankless they often introduce more troubles than
they solve. slow arrival of hot water upon turn on, unit must detect
water being used, turn on burner and get hot before you get any hot
water, no hot water in low flow like valve open just a little to wash
hands, cool hot water in areas where incoming water is cold in winter,
no hot water at all during power failures, need upgraded gas lines and
possibly flue for proper operation, and standby losses of regular tank
are really lost during heating season they help heat your home,
although during AC use they can add to the heat load some. plus the
energy you save will never exceed the higher initial cost of the
tankless, espically considering they need regular service.

normal tanks are very reliable and tend to not have technical troubles
till they leak.

so whats up with your install