Error code 29 appears; unit may shut down during operation, especially on condensing Noritz models with condensate drain.

Safety first: Turn OFF power to the heater. Condensate is mildly acidic; wear gloves and eye protection when handling.

Steps to check and correct:

• Inspect condensate drain line: Locate the condensate outlet at the bottom of the Noritz condensing unit. Follow the drain tubing to its termination. Ensure there are no kinks, sags, or blockages. Clear any visible obstructions and verify continuous downward slope.
• Clean condensate trap: If your model has an external or internal trap, remove it per the service manual. Flush with clean water to remove slime, debris, or scale. Reinstall, ensuring all seals are tight.
• Check condensate neutralizer: Many Noritz condensing models use a neutralizer cartridge. Inspect for saturation (media turned to mush or fully discolored). Replace the neutralizer cartridge if clogged or past service life.
• Verify drain termination: Ensure the drain terminates to an approved location with an air gap and is not submerged or blocked.
• Reset and test: Restore power and run the unit. If error 29 persists, the condensate level sensor or related wiring may be faulty and should be checked by a technician.