Rheem Tankless User Manual

http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html

Use remote control to set temperatures up to 120ºF

Test current temperature with cooking thermometer at different sinks and faucets.

Remote is factory set to 100ºF

Use dip switches to adjust above 120

To adjust temperature higher than 120ºF <> up to 140ºF, then read your specific product manual for dip switch settings. Information here will apply to SOME models. Heavy duty models can be adjusted up to 180ºF

Dip switch settings should be adjusted by professionally trained person only.

If temperature rise is too much for incoming water temperature, or venting capacity, or air supply or gas supply, or combination of factors, then tankless will shut off.

Turn off remote control. Turn off the gas and water shutoff valves.

Remove front cover.

Find DIP Switch #4 located at the top left hand side of PCB.

Change the DIP Switch #4 setting to the “ON” position. DO NOT alter any other DIP Switch. The LED on the PCB is flashing. At the same time, the display of the Main Remote Control starts to flash.

Press the “SW1” button on the left hand side of the PCB for more than 1 second. The LED on the PCB starts illuminating continuously. At the same time, the display of the Main Remote Control is on continuously.

Change the DIP Switch #4 setting back to the “OFF” position. DO NOT alter any other DIP Switch. The LED on the PCB will stop illuminating. At the same time, the display of the Main Remote Control will turn off.

Attach the unit’s front cover.

Turn on the remote control, gas and water shutoff valves.

Check and ensure safe operation and performance of the water heater.

Dip Switches have to be moved in exact sequence shown instructions above

You want 140º from tankless? And incoming water temperature is 50º Temperature rise is 140º subtract 50º = 90º, so gallons per minute (GPM) will fall

Flow rates

Flow rates depend on temperature of incoming water –and- capacity of tankless unit.

Chart below is based on 65º incoming water temperature, which is average year-round for Southern States. Average year-round for mid-Illinois is approx 54º. Chart below is skewed toward warmer climates.

Place cooking thermometer under cold water tap to get comparison reading. Fig 1 Numbers are for new tankless working at optimal performance

Typical shower uses 2.5 gallons per minute, typical faucet 2 gallons per minute

The hotter the shower water, the more cold water is used.