52
Noritz Modulating Gas Valve Signal Fault

Error code 52 appears; unit may not fire or may shut down.

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Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

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Possible Causes

Defective gas valve assembly, Open or shorted gas valve wiring, PCB output failure to gas valve, Incorrect gas valve type installed

How to Fix / Troubleshooting

Safety first: Turn OFF gas and power. Gas valve work must be performed by a licensed professional.

Steps to check and correct (for technicians):

  • Inspect gas valve wiring: Verify that the modulating gas valve connector is fully seated and wires are intact.
  • Check coil resistance: Using a multimeter, measure gas valve coil resistance and compare to Noritz specifications. Replace the gas valve assembly if out of range.
  • Verify correct part: Ensure the installed gas valve matches the model and gas type (NG/LP) specified by Noritz.
  • Test PCB output: With proper tools, verify that the PCB is sending the correct control signal to the valve during operation.
  • Replace components as needed: If the valve is defective, replace it and perform leak testing. If PCB output is faulty, replace the PCB.

Homeowner note: Do not attempt to disassemble or adjust the gas valve yourself; contact a qualified Noritz technician.

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Repair Difficulty

Professional Required 5/5

Required Part

Gas Valve Assembly
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