Other: Tankless Water Heater tips

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

Read live data (Status Information menu)

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

Shows live readings such as flow, temperatures, exhaust temperature, flame AD value, fan RPM, APS voltage, model, gas and firmware.

1. Press Menu.
2. Choose 2. Status Information and scroll to the reading.

Read the error history

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

The last 10 errors are listed in the menu.

1. Press Menu.
2. Choose 3. Error History to see the last 10 errors.

Check the recirculation mode (MM86)

Noritz · NRCR92, NRCR111

MM86 confirms which recirculation mode the unit is really set to.

1. Open the maintenance monitor and select MM86.
2. Read the value: dedicated return 11 Auto Recirc (default), 12 Manual timer, 13 Always ON, 14 Always OFF, 15 On-Demand (Title 24).
3. Crossover valve units show 21 to 25 for the same modes in the same order.

Read live data (Maintenance Monitor)

Noritz · EZ111, EZ98, EZ71, NRCR111, NRCR92 (operation panel and RC-7651M-B remote)

The Maintenance Monitor menu shows live unit data as MM numbers.

1. Press the Menu button.
2. Use Up/Down to select Maintenance Monitor, press OK.
3. Pick the MM item to read.
4. Press Back to leave.

Read the error history

Noritz · EZ111, EZ98, EZ71, NRCR111, NRCR92 (operation panel and RC-7651M-B remote)

Shows the eight most recent failures, 1 being the newest.

1. Press the Menu button.
2. Open Maintenance Monitor.
3. Select an error and press OK for details.

Read the error history through maintenance monitors MM91-MM98

Noritz · Noritz NRCR92 / NRCR111

On NRCR units the error history is also read in maintenance monitor mode.

1. Open the maintenance monitor.
2. MM91 is the most recent error code.
3. MM92 to MM98 are error codes 2 to 8, next most recent first.

Gas orifice identification

Rinnai · Gas valve orifice check, Code 11

The gas orifice in the gas valve shows the gas type.

1. Red orifice means propane (L.P.).
2. Blue orifice means natural gas.
3. Confirm the orifice matches the gas type on the rating plate.