No, a tankless water heater does not have to be installed on an outside wall inside the home. It can be installed anywhere inside the house as long as it can be properly vented to the outside. The type and length of the vent will impact the installation cost. Keep in mind tankless water heaters generally operate at noise levels between 40 to 60 decibels (dB). For comparison, 40 dB is roughly equivalent to the noise level of a quiet library, while 60 dB is similar to the sound of a normal conversation. The exact noise level can vary based on the model and installation quality.
