Rheem Tankless Hot Water Heater Rtg-74pvp-2 7.4 Gpm

Tankless Water Heater Error Code List Code

Fault

Remedy

00

1 Hour continuous combustion

05

Imperfect Combustion Alarm

10

Air Supply or Exhaust Blockage

11

No Ignition

12

Flame Failure

14

Overheat Wrap Fault

15

Boiling Safety Device

16

Over Temperature Warning

Close all hot water taps to reset unit. Turn off, or remove circulation pumps (unit is not designed for continuous operation with circulation systems). Clean air inlet filter. Clean combustion air fan. Clean heat exchanger fins. Check for adequate combustion air ventilation openings and clean if necessary. Check vent system for partial blockage and correct as necessary. Check all vent components for proper connections. Check that nothing is blocking the flue inlet or exhaust. Ensure proper venting materials were used. Ensure condensation collar was installed correctly. Ensure heat exchanger fins, fan, and air intake are not blocked. Ensure you have gas to the appliance. Ensure gas type and pressure is correct. Bleed all air from gas lines. Ensure gas line, meter, and regulator are sized properly. Ensure appliance is properly grounded. Check gas solenoid valves for open or short circuits. Ensure igniter is operational. Check igniter wiring harness for damage. Ensure you have gas to the appliance. Ensure gas type and pressure is correct. Bleed all air from gas lines. Ensure flame rod wire is connected. Check flame rod for carbon build-up. Ensure gas line, meter, and regulator are sized properly. Ensure appliance is properly grounded. Check gas solenoid valves for open or short circuits. Check power supply for loose connections. Check power supply for proper voltage and voltage drops. Disconnect remote control. Disconnect and re-connect all wiring harnesses on unit and PC board. Ensure proper venting material was installed. Ensure condensation collar was installed properly. Ensure maximum vertical vent length does not exceed allowable limits. Ensure maximum horizontal vent length does not exceed allowable limits. Ensure high fire and low fire manifold pressure are correct. Check gas type of unit and ensure it matches gas type being used. Check heat exchanger for cracks and/or separations. Ohm out safety circuit. Check for improper conversion of product. Check for restrictions in air flow around unit and vent terminal. Check for a foreign materials in combustion chamber and/or exhaust piping. Check for closed water heater inlet valve or restrictions in cold water inlet pipe (must be fully open). Check for clogged heat exchanger (scale buildup). On commercial water heater, lower setpoint temperature below 180F at high altitude. Check for clogged heat exchanger. Check for restrictions in air flow around unit and vent terminal. Check for a foreign materials in combustion chamber and/or exhaust piping. 1 of 3

Tankless Water Heater Error Code List Code 21 24

29 31

Fault

Remedy

Malfunction of Air Intake Filter Switch Malfunction of Operational Switch

Make sure air filter door is properly seated. Make sure front panel is properly installed. Press max button on PCB to reset. Press min button on PCB to reset. Replace PCB Clean heat exchanger air inlet

Heat Exchanger Outlet Temp. Too Low Water Inlet Temperature Sensor Fault

33

Outgoing Water Temperature Sensor Fault

34

Combustion Air Temperature Sensor Fault

35

Improper Thermistor Connections Gas Inlet Solenoid Valve Fault Modulating Solenoid Valve Fault

51 52

61

Combustion Fan Failure

71

Gas Inlet Solenoid Valve Control Fault

72

Flame Sensing Device Fault

76

Communication Fault with Remote Control

79

Fan Motor Current Fault

Check sensor wiring for damage. Ohm out sensor Check and clean scale from sensor. Replace sensor. Check sensor wiring for damage. Ohm out sensor Check and clean scale from sensor. Replace sensor. Check sensor wiring for damage. Ohm out sensor Check and clean scale from sensor. Ensure fan blade is tight on motor shaft and it is in good condition. Check for restrictions in air flow around unit and vent terminal. Replace sensor. Check that all thermistors are connecte