Tankless means upgrading your gas line.
When going from a tank to tankless, there is a myth that says you always need to upsize the gas supply line. This isn’t always the case. Rinnai condensing tankless water heaters’ zero governor gas valve, switching venturi, and turbo fan work together to pull in the right mixture of gas and air to produce an energy-efficient combustion. This allows the tankless water heater to self-compensate for any fluctuations in gas or air supply. The Tankless Truth is, in many cases, you don’t need to upgrade your gas supply line when going tankless.
Other Common Myths
Stainless steel heat exchangers are better.
Tankless is a new tech that is unproven.