Settings shortcuts: Tankless Water Heater tips

Short, practical technician tips on settings shortcuts for tankless water heater. Check each one against the manual for your exact model before acting.

Adjust recirculation parameters P12, P14, P15

Navien · Navien NPN non-condensing tankless water heaters: NPN-160U/180U/199U (universal, indoor or outdoor with vent kit) and NPN-120E/160E/180E/199E (outdoor only)

Recirculation pump cycle, sampling time and differential OFF temperature are set in the R&D menu.

1. Turn the unit off, press Up 3 times, Down 3 times, Up 4 times.
2. Choose 2.PAR and press Info.
3. Press Info to edit and use +/- to change; the value sends after Info or 10 s without input.
4. Reset returns to the previous menu.

Change gas type with the front panel DIP switch

Navien · Navien NPE-A2 (built-in recirculation) and NPE-S2 condensing tankless water heaters: NPE-150S2, NPE-180A2/S2, NPE-210A2/S2, NPE-240A2/S2

Front panel DIP switch 1 selects natural gas or propane; use it only after a gas conversion.

1. Turn power off before changing DIP switches.
2. Switch 1: OFF = natural gas (factory), ON = propane.
3. Change it only after a gas conversion with the Navien kit; the unit shows E788 until the gas type is confirmed in the Start-Up Wizard.

Enable Commercial Mode (up to 185 F)

Navien · Navien NPE-A2 (built-in recirculation) and NPE-S2 condensing tankless water heaters: NPE-150S2, NPE-180A2/S2, NPE-210A2/S2, NPE-240A2/S2

Commercial Mode raises the allowed set temperature range; the front panel temperature lock must be off.

1. Turn power off and set front panel DIP switch 2 (temperature lock) to OFF.
2. Hold Menu + Back 3 s > 1. Installer Menu (password 1234) > 2. Parameter Settings.
3. Open 12. Commercial Mode: Enable = 140-185 F, Disable = 97-140 F (default).

Lock the temperature setting (commercial lock, DIP switch 7)

Navien · Navien NPN non-condensing tankless water heaters: NPN-160U/180U/199U (universal, indoor or outdoor with vent kit) and NPN-120E/160E/180E/199E (outdoor only)

DIP switch 7 stops users changing the set temperature.

1. Switch 7: OFF = temperature can be set, ON = temperature cannot be set.

Lock the temperature setting (front panel DIP switch 2)

Navien · Navien NPE-A2 (built-in recirculation) and NPE-S2 condensing tankless water heaters: NPE-150S2, NPE-180A2/S2, NPE-210A2/S2, NPE-240A2/S2

Front panel DIP switch 2 stops users changing the set temperature.

1. Turn power off before changing DIP switches.
2. Switch 2: OFF = temperature can be set, ON = temperature cannot be set.
3. Keep it OFF if you want to use Commercial Mode.

Set the altitude setting

Navien · Navien NPE-A2 (built-in recirculation) and NPE-S2 condensing tankless water heaters: NPE-150S2, NPE-180A2/S2, NPE-210A2/S2, NPE-240A2/S2

Altitude is a numbered installer parameter on the NPE-2.

1. Hold Menu + Back 3 s > 1. Installer Menu (password 1234) > 2. Parameter Settings.
2. Open 14. Altitude Setting and pick 1 (0-2,000 ft), 2 (2,000-5,400 ft), 3 (5,400-7,700 ft) or 4 (7,700-10,100 ft). Default is 1.

Set a temperature of 125 F (55 C) or higher

Noritz · Noritz EZ111/EZ98/EZ71 and NRCR111/NRCR92

Settings of 125 F (55 C) or higher need the Max Set Temperature raised first; the panel warns about scald risk.

1. With the unit power off, raise Max Set Temperature (100-140 F, default 120 F / 50 C).
2. Then set the temperature to 125 F (55 C) or higher.

Switch the controller between Celsius and Fahrenheit

Rinnai · Rinnai SENSEI, SENSEI RX/CX and KCM tankless with a controller

Changes the temperature units shown on the controller.

1. With the water heater OFF, press and hold On/Off on the controller for 5 seconds.
2. The display switches between °C and °F. Repeat to switch back.

Turn controller key beeps on or off

Rinnai · Rinnai SENSEI, SENSEI RX/CX and KCM tankless with a controller

Switches the beep that sounds when controller keys are pressed.

1. Press and hold Up and Down together until a beep is heard (about 3 seconds on SENSEI and RX/CX, about 5 seconds on the KCM MC-601-US), then release.
2. Repeat the same press to turn the beeps back on.