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Noritz · Tankless water heater

29 Condensate collector water level abnormal

Medium severity Noritz NRC/NRCP

What the control is telling you

Condensate is backing up in the condensate collector of a non-premix condensing unit (NRC/NRCP). The deck only covers the drain line routing.

Applies to: Noritz NRC/NRCP and older non-premix condensing units

Likely causes

  • Drain line smaller than 1/2 in., too long or with flat horizontal runs
  • Drain line pitched up after a horizontal section, or a trap formed in the line
  • Valves added to the drain line, or no air gap at the end
  • Blocked or frozen drain line or failed condensate pump

Test and repair steps

  1. Check the condensate line at least 1/2 in., short and direct.
  2. Any horizontal run must slope down away from the unit (1/4 in. per foot); never pitch it back up.
  3. Remove any valves from the drain line and make sure the end has an air gap.
  4. If a condensate pump is used, check the pump and its 3/8 in. ID tubing.
  5. Clear blockages or ice from the line and confirm condensate flows.

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Source: Noritz Residential Level 2 Maintenance & Troubleshooting (NRC/NRCP and older, R2 V1), 29 error code, p.8. Summarized in our own words; check the original manual for your model.

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For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.