Rinnal r75ls was installed in our home 6 years ago. started giving error code 10. Bought a new 75RS because this should have been easier. But no Rinnai changed the location of both the hot and cold lines. The new one does not fit without major piping changes. If you want a new hot water heater do not buy a Rinnai, they don't last and in our case changing the water line location was a big pain.