Code 73 on a noritz tankless propane water heater

Remove the bird's nest in the flue.

The 10, 59, 90 and 99 error codes indicate that a Noritz heater has experienced a combustion abnormality. In most cases, it is the result of an obstruction in the heater's flue. Examine the flue to see if it is blocked by debris and clean if necessary.

How To Resolve The Seven Most Common Noritz Tankless ...

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Nov 16, 2015 - This error code involves a breakdown in communication between two tankless water heaters using the Quick Connect Cord. It can occur when more ...

Troubleshooting Noritz Tankless Water Heaters and Error Codes

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Error code 90 and 99 ... Action: Check for the obstructed venting, improper gas burning (flame shape and color change). Ensure the water heater gets the ...

Error Codes for a Noritz Water Heater - Waterheatertimer.org

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For a Noritz tankless water heater, error number 78 indicates a problem with the fan motor. The instructions below will help you clear the problem number 78 on a Noritz tankless water heater:

1. Turn off the power to the tankless water heater by either disconnecting it or switching off the circuit breaker.
2. Verify that the fan motor is clear of any obstructions or debris that may be preventing it from operating properly.
3. Check the fan motor is receiving power by measuring the voltage across the fan leads with a voltmeter. Verify that the electrical connections to the fan motor are secure if there is no voltage.
4. If the fan motor is broken or not operating properly, it may need to be replaced. For further assistance with the repair or replacement of the fan motor, you can contact Noritz technical support or a certified HVAC specialist.
5. After resolving the issue with the fan motor, switch off the power to the tankless water heater for at least 30 seconds before turning it back on. This will clear the error code and restore normal operation to the device.
6. If you are unclear or uncomfortable with any of these processes, you should seek the aid of a certified HVAC specialist or Noritz technical support.

Call noritz
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Don't buy a tankless water heater.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

The NC250 (N-0931M) Series ASME Tankless Water Heater is a commercial grade water heater and many people install the vent wrong. PVC CANNOT be used for venting. The NC250-DV-ASME is for indoor use only. Improper venting will cause the symptom you describe.

There's a field conversion kit available. Contact Noritz to get more information.

There is no error 43 on a NR71. There is a 73 error code which is caused by disconnecting jumper cables while the power is on.

There's a filter on the cold water side of the unit. You'll notice a black, plastic, cylindrical component directly below the unit on the cold water line pointing to the left. If you shut of your water and unscrew that cap, there will be a filter attached to the other end.

If the filter is clean, I'd recommend calling tech support for help. You might have an error code.

The 59 code is typically caused by insufficient gas supply to the unit. It can also be caused by obstructed exhaust flow, stuck exhaust damper (located directly on top of the unit's exhaust), insufficient makeup air, or improperly installed venting (i.e. too long or too many elbows).

I would recommend initially checking the incoming gas pressure at the gas connection on the unit. The gas pressure should not drop below 5" water column for a natural gas unit, 8" for a propane system (the unit need to be operating at its maximum output).

I don't think clean until you remove it.the clean it well and fine waterless lub.for it

I called Noritz error code 16 is a overheat problem. Noritz say's to flush your coil with vinegar or CLR.
Use a small pump to recirculate the CLR or vinegar through the system for 45 minutes and flush with fresh water. This worked for me.