Noritz Error Code 65: Main water control servo abnormality (Tankless)
Noritz error code 65 on a tankless water heater means: Main water control servo abnormality. It is also called Noritz diagnostic code 65.
Homeowner? What Noritz code 65 means for you
Check, then call Your tankless water heater is reporting: Main water control servo abnormality. This is often caused by something simple. Try the safe checks below; if the code returns, book a service call before it turns into a no-heat or no-hot-water emergency.
Safe things you can check yourself
- Check that gas reaches the house: other gas appliances work, or the propane tank is not empty.
- Make sure the heater is plugged in and its breaker is on. In winter, keep the power on: it protects the unit from freezing.
- Outside, make sure the intake and exhaust pipes or vent cap are not blocked by snow, ice, leaves or a nest.
- Check that the hot and cold water valves under the heater are fully open.
- If you have a remote controller, turn it off and on once. If the code comes back, call a technician.
Call (647) 657-2977Book a service call
Licensed technicians serving Vaughan, Toronto and the GTA.
What does Noritz error code 65 mean?
The board cannot communicate with or position the main water flow control servo. Same meaning on all families; hard water and scale are a listed cause.
Applies to: All Noritz residential tankless (EZ, NRCR, NCC199CDV, NRC/NRCP)
Common causes of Noritz code 65
- Scale or debris in the main servo
- Failed servo motor
- Wiring/connector fault
A technician checks these and 1 other possible causes on site before replacing any part.
Noritz models that use code 65
EZ71DVEZ98DVEZ111DVN-0841MCN-0841MC-DVN-0842MCN-0842MC-DVNCC199CDVNRC111-DVNRC111-SVNRCR92DVNRCR111DV
Other Noritz Tankless codes
All Noritz Tankless Water Heater error codes →
Noritz code 65: homeowner questions
What does Noritz code 65 mean?
Main water control servo abnormality. The board cannot communicate with or position the main water flow control servo. Same meaning on all families; hard water and scale are a listed cause.
Is it safe to keep using my tankless water heater with code 65?
It depends on the cause. This is often caused by something simple. Try the safe checks below; if the code returns, book a service call before it turns into a no-heat or no-hot-water emergency.
Can I reset Noritz code 65 myself?
You can try one reset (power off for 30 seconds, then on). If Noritz code 65 comes back, the cause is still there and a licensed technician should check it.
Who can fix Noritz code 65 near me?
Aurora Star Tech Inc. repairs Noritz tankless water heaters in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.
Homeowner help: Tankless Water Heater No Hot Water: What to Check
Troubleshooting guides
- No hot water All brands · Tankless Water Heater
- Water temperature fluctuates All brands · Tankless Water Heater
- Cleaning ignition and flame rods - Noritz Noritz · Tankless Water Heater
- Cleaning the fan and burner - Noritz EZ/NRCR/CDV Noritz · Tankless Water Heater
- Descaling (flushing) the heat exchanger - Noritz Noritz · Tankless Water Heater
- Draining to prevent freezing - Noritz EZ/NRCR Noritz · Tankless Water Heater
- Field gas conversion NG to LP - Noritz NRCR/EZ Pro Noritz · Tankless Water Heater
- Heat exchanger replacement - Noritz NRC111 / NCC199 Noritz · Tankless Water Heater
- Heater does not fire when hot water is opened - Noritz tankless Noritz · Tankless Water Heater
- Recirculation not working or hot water slow - Noritz NRCR Noritz · Tankless Water Heater
- Water not hot enough or temperature fluctuates - Noritz tankless Noritz · Tankless Water Heater
Source: Noritz EZ/NRCR/CDV Level 2 Maintenance & Troubleshooting (Premix R2 V2), 65 & 66 error codes, p.15; Noritz Residential Level 2 Maintenance & Troubleshooting (NRC/NRCP and older, R2 V1), Water control route and 65 & 66 error codes, p.3-4, 9; Noritz NRCR Pro training (NRCR92/NRCR111, Printable V3), Poor water quality issues, p.32. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.