For whole-house hot water on demand, Bosch Thermotechnology offers the wall-mountable Tronic 5000C and 6000C electric water heaters. The compact and lightweight units deliver 97% thermal efficiency with minimal standby loss, and have modulating elements that help ensure a constant GPM output temperature. A filter screen on the units' inlets provides enhanced scale-buildup resistance over time. Tronic C models require hard-wiring. For colder climate areas where the average ground water temperature is less than 60 degrees F, the Tronic 6000C model WH17 is recommended for point-of-use applications only. Other models (Tronic 6000C WH 27 and Tronic 5000C WH36) may be suitable for whole-house use.