Single unit undersized for a five or six bath estate
Why here: A large soaking tub filling while two showers run will exceed the roughly 5.5 to 6 GPM a single 199,000 BTU unit produces at a North Texas winter rise, and the temperature drops for everyone.
What we do: We count fixtures and calculate peak simultaneous flow, then specify either a single high-output unit with a recirculation loop or two units manifolded with a shared controller.