I really like tankless water heaters but I do admit they are not always practical for many houses due to fact that often times gas supply lines must up upsized and along with difficulties with venting can greatly increase costs. . However, if practical, the Rinnai tankless brand has proven to be a high quality winner! I have also had success and customer satisfaction with Navien tankless water heaters. The cool thing about tankless is that your entire family (and neighbors too!) can shower back to back and you will never run out of hot water; and when you are on vacation or away, the water heater never runs.