33 🟡 Repair Required
Noritz Error Code 33: Heat Exchanger Thermistor Failure
⚠️ Your Noritz water heater is locked out due to a heat exchanger thermistor failure. It's safe to operate, but needs professional repair.
How to Fix Noritz Code 33
- Check if the water heater is still under warranty. If so, contact Noritz for repair or replacement.
- Turn off the power to the water heater at the circuit breaker for safety.
- Contact a licensed HVAC technician for repair. Do not attempt to fix this issue yourself.
What Does Noritz Error Code 33 Mean?
The error code 33 on your Noritz water heater indicates a failure in the heat exchanger thermistor. This component measures the temperature of the heat exchanger and sends this information to the control board. When it fails, the system locks out to prevent overheating and potential damage. This is a common issue in Noritz water heaters and is typically caused by normal wear and tear or exposure to hard water.
Common Causes of Noritz Code 33
- Wear and tear over time
- Exposure to hard water
- Manufacturing defect
- Electrical short or open circuit
Applicable Noritz Models
Need a Pro to Fix Noritz Code 33?
A licensed HVAC technician can diagnose and fix this issue quickly.
Find a Licensed Tech Near You →Replacement Parts for Noritz Tankless Water Heater Code 33
Heat Exchanger Thermistor OEM: NOR-30066