What temperatures should I expect?

The simple answer- a constant, steady 120 degrees (or as set). More precisely, tempering (mixing) valves precisely regulate final temperatures at the faucet. Hot water temperatures leaving the SHEM tank are variable, depending on flow rate and tank temperatures. Summer tank temperatures can regularly exceed 150 degrees, thus the need for a tempering valve. Winter's cloud cover will greatly reduce production, and a backup source of hot water will be required.

Flow rates have a major impact on final temperatures. The SHEM tank will produce hot water one degree less than tank temperature under a flow rate of 1 gallon per minute. Increasing the flow rate to 4 gallons per minute (three plus showers at once) results in an 11 degree difference between tank and water temperatures.