Stiebel Eltron DHC tankless water heatersare designed for installation at the point-ofuse. The DHC heats water instantaneouslyas it flows through the unit. Stand-by heatlosses are completely eliminated.The heating element is controlled by aflow switch which means a DHC can neverdry-fire and fail prematurely. And since allDHCs are hydraulically controlled, operationis quiet. DHC water heaters are equippedwith a safety high-limit with manual reset.The rugged all copper design ensures manyyears of reliable service.DHC 3-1, DHC 3-2 and DHC 4-2 modelsare shipped with 0.5 GPM pressurecompensating flow reducer/aerators thatfit on most faucets. Flow controls andfaucet aerators are highly recommended inconjunction with tankless water heaters. Nopressure relief valve, drains, or circulatingpumps needed