How House Works

Noritz 29 (condensate drain or air pressure switch): what to check

By How House Works EditorialBased on Noritz manualsChecked against sources Updated

Noritz display

29

“Clogging of condensate trap or drain pipe”

EZTR40, NRC661A/NRC711, NRC661, NRC98/NRC111/NERC, NRC (2013) · NRC98 Owner's Guide Rev. 01/17, p. 28; NRC111 Owner's Guide Rev. 01/17, p. 28; NERC98DV Owner's Guide Rev. 11/19, p. 28; NERC11DV Owner's Guide Rev. 11/19, p. 28; NRC83/NRC98 Owner's Guide Rev. 03/13, p. 26; NRC1111 Owner's Guide Rev. 03/13, p. 27; EZTR40 Owner's Guide Rev. 01/17, p. 24; NRC661A/NRC711 Owner's Guide Rev. 01/17, p. 25; NRC661 Owner's Guide Rev. 01/13, p. 25
Owner checks, then technician

Other models use 29 for other faults. NRCP (Er:29): “Air Pressure Switch Abnormality” (NRCP1112/NRCP982 Owner's Guide Rev. 05/19, p. 39; NRCP111/NRCP98 Owner's Guide Rev. 05/19, p. 34). NRC111 Owner's Guide Rev. 09/09: “Clogging of neutralizer” (p. 27). EZ technical sheets: “External Condensate Pump abnormality”, shown only if an external condensate pump is interlocked with the heater (EZ Technical Sheet FPFK081, p. 1), and “Condensate pump abnormality (Only if connected to the water heater)” (EZ Technical Sheet FHCK080, p. 1). EZTR40, NRC661A/NRC711 and NRC661 sheets: “Condensate Container clogging” (EZTR40 Technical Sheet EXSK072, p. 1). Field Manual KS-11-0004: “Neutralizer Water Level Electrode Abnormality” (p. 26).

What it means

What 29 means depends on the model:

  • NRC98, 2017 NRC111, NERC, NRC83, NRC1111, EZTR40, NRC661A/NRC711 and NRC661: clogging of the condensate trap or drain pipe NRC98 Owner’s Guide Rev. 01/17, p. 28; EZTR40 Owner’s Guide Rev. 01/17, p. 24.
  • NRC111-SV and NRC111-DV from 2009: clogging of the neutralizer NRC111 Owner’s Guide Rev. 09/09, p. 27.
  • NRCP: Er:29, an air pressure switch abnormality NRCP1112/NRCP982 Owner’s Guide Rev. 05/19, p. 39.
  • EZ and NRCR: 29 is not in the owner’s guides. Noritz’s technical sheet lists it as an external condensate pump abnormality that shows only if such a pump is interlocked with the heater EZ Technical Sheet FPFK081, p. 1.

The EZTR40 guide says condensate drains from the drain pipe at up to about 0.8 gallons per hour (3 liters per hour), that this is not a water leak, and that the condensate is acidic, with a pH of about 2–3 EZTR40 Owner’s Guide Rev. 01/17, p. 8.

Check these first

NRC98, 2017 NRC111, NERC, NRC83, NRC1111, EZTR40, NRC661A/NRC711 and NRC661 heaters:

  1. Check whether the condensate drain pipe is clogged or frozen NRC98 Owner’s Guide Rev. 01/17, p. 28; EZTR40 Owner’s Guide Rev. 01/17, p. 24. Do not plug or block the drain line; it must always drain freely EZTR40 Owner’s Guide Rev. 01/17, p. 8. The EZTR40 guide’s periodic inspection also asks you to check for blockage at the drain pipe discharge EZTR40 Owner’s Guide Rev. 01/17, p. 21.
  2. If the heater has been out of use for a long time, the condensate trap has to be filled with water to keep dangerous exhaust gases out of the building. The EZTR40 guide fills it this way: make sure the area is well ventilated, opening a window or door if needed, then run the heater and check that condensate comes out of the drain pipe. In normal use that starts within 15 minutes, though it can take longer EZTR40 Owner’s Guide Rev. 01/17, p. 20.
  3. The guide’s next step is to contact the installer or Noritz America Technical Support for assistance NRC98 Owner’s Guide Rev. 01/17, p. 28. The NERC98DV and NERC11DV guides name Thermalux Customer Care instead NERC98DV Owner’s Guide Rev. 11/19, p. 28.

NRCP heaters (Er:29):

  1. Press the Power button to clear the code. Er.29 is a hard lockout, which clears when Power is pressed off and then on NRCP1112/NRCP982 Owner’s Guide Rev. 05/19, p. 39; NRCP111/NRCP98 Owner’s Guide Rev. 05/19, p. 34.
  2. If the code is still there, make sure the exhaust pipe is free of obstructions and that the condensate trap and drain pipe are not clogged NRCP111/NRCP98 Owner’s Guide Rev. 05/19, p. 34.
  3. The same row also lists cleaning the intake air filter. That filter sits behind the front cover: the guides’ procedure starts with turning the heater off, disconnecting its power and removing four front cover screws NRCP1112/NRCP982 Owner’s Guide Rev. 05/19, p. 35; NRCP111/NRCP98 Owner’s Guide Rev. 05/19, p. 30. The same guides also say not to install, repair or service the heater yourself and not to disassemble it NRCP1112/NRCP982 Owner’s Guide Rev. 05/19, pp. 6, 10; NRCP111/NRCP98 Owner’s Guide Rev. 05/19, pp. 5–6. Because the step opens the cabinet of a gas appliance, we list it as technician work.
  4. If Er:29 happens again, contact the installer or Noritz America Technical Support NRCP1112/NRCP982 Owner’s Guide Rev. 05/19, p. 39.

When to call a licensed technician

  • No water comes out of the end of the drain line. A qualified service technician must clean the condensate line EZTR40 Owner’s Guide Rev. 01/17, p. 20.
  • The NRCP intake air filter, which sits behind the front cover NRCP1112/NRCP982 Owner’s Guide Rev. 05/19, p. 35.
  • The drain line itself. The EZTR40 installation manual says horizontal runs must slope 1/4 in. per foot toward the drain or condensate pump, the line must not have a trap, and an external neutralizer must be installed where local code requires one or where the condensate could cause damage EZTR40 Installation Manual Rev. 11/20, p. 24.
  • The neutralizer on a 2009 NRC111. The guide says to contact the installer or Noritz America Technical Support; codes 92 and 93 on the same models mean the neutralizer needs replacing soon or has reached the end of its life NRC111 Owner’s Guide Rev. 09/09, p. 27.
  • An external condensate pump on an EZ heater. The technician’s checks are the pump for blockage and its connector for damage EZ Technical Sheet FPFK081, p. 1.

Notes for different models

  • On NRCP heaters 29 is an air pressure switch code, yet the NRCP1112/NRCP982 guide’s list of hard-lockout codes labels it “Er.29_Condensate line” NRCP1112/NRCP982 Owner’s Guide Rev. 05/19, p. 39. The NRCP111/NRCP98 data sheet adds a check that the condensate line slopes down NRCP111/NRCP98 Technical Data Sheet Rev. 07/19, p. 2.
  • The 2024 EZ sheet also lists 293, the 2025 sheet 29-3 EZ Technical Sheet FHCK080, p. 1; EZ Technical Sheet FPFK081, p. 1. The EZ installation manual has a step to confirm that “External Condensate Pump Triggered 29” appears on the operation panel EZ Installation Manual Rev. 10/25, p. 49.
  • Field Manual KS-11-0004 (October 2012; NRC83, NRC98, NRC1111, NR981, NR83-DVC) and Field Manual June 2011 call 29 “Neutralizer Water Level Electrode Abnormality” in tables that do not say which models show it Field Manual KS-11-0004, p. 26; Field Manual June 2011, p. 34.
  • The NR and NER66OD owner’s guides do not list 29.

Related Noritz codes

  • 90 “(1) [When supplying combustion air from the indoors] The air supply vent may be clogged. (2) Exhaust vent may be clogged. (3) Abnormal combustion, low gas supply pressure. (4) Condensate drain line may be clogged.”
  • 92 “The neutralizer needs to be replaced soon.”
  • 93 “The neutralizer has reached the end of its service life and must be replaced.”

All Noritz codes

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Sources

  1. NORITZ America Corporation. EZTR40 Owner's Guide Rev. 01/17. SBB809K-2, Rev. 01/17; covers NRC663-FSV (EZTR40). Accessed Oct 12, 2026.
  2. NORITZ America Corporation. NRC661A/NRC711 Owner's Guide Rev. 01/17. SBB8067-4, Rev. 01/17; covers NRC711-DV, NRC711-OD, NRC661A-DV and NRC661A-OD. Accessed Oct 12, 2026.
  3. NORITZ America Corporation. NRC661 Owner's Guide Rev. 01/13. SBB801H, Rev. 01/13; covers NRC661-DV and NRC661-OD. Accessed Oct 12, 2026.
  4. NORITZ America Corporation. NRC98 Owner's Guide Rev. 01/17. SBB80JP-3, Rev. 01/17; covers NRC98DV (GQ-C2857WS-FF US) and NRC98OD (GQ-C2857WS US). Accessed Oct 12, 2026.
  5. NORITZ America Corporation. NRC111 Owner's Guide Rev. 01/17. SBB80HS-3, Rev. 01/17; covers NRC111DV (GQ-C3257WX-FF US) and NRC111OD (GQ-C3257WX US). Accessed Oct 12, 2026.
  6. NORITZ America Corporation. NERC98DV Owner's Guide Rev. 11/19. SBB818C-1, Rev. 11/19; covers NERC98DV (GQ-C2857WS-FF ET US); contact lines name Thermalux Customer Care, 855-960-3434. Accessed Oct 12, 2026.
  7. NORITZ America Corporation. NERC11DV Owner's Guide Rev. 11/19. SBB818A-1, Rev. 11/19; covers NERC11DV (GQ-C3257WX-FF ET US); contact lines name Thermalux Customer Care, 855-960-3434. Accessed Oct 12, 2026.
  8. NORITZ America Corporation. NRC83/NRC98 Owner's Guide Rev. 03/13. SBA8884-1, Rev. 03/13; covers NRC98-DV, NRC98-OD, NRC83-DV and NRC83-OD. Accessed Oct 12, 2026.
  9. NORITZ America Corporation. NRC111 Owner's Guide Rev. 09/09. SBA8370, Rev. 09/09; covers NRC111-SV and NRC111-DV. Accessed Oct 12, 2026.
  10. NORITZ America Corporation. NRC1111 Owner's Guide Rev. 03/13. SBA8723-1, Rev. 03/13; covers NRC1111-DV and NRC1111-OD. Accessed Oct 12, 2026.
  11. NORITZ America Corporation. NRCP1112/NRCP982 Owner's Guide Rev. 05/19. Rev. 05/19, no SB number printed; title line: NRCP1112-DV / NRCP982-DV (Eco TOUGH). Accessed Oct 12, 2026.
  12. NORITZ America Corporation. NRCP111/NRCP98 Owner's Guide Rev. 05/19. Rev. 05/19, no SB number printed; covers NRCP111-DV and NRCP98-DV (listed by Noritz as the 2019 models). Accessed Oct 12, 2026.
  13. NORITZ America Corporation. EZ Technical Sheet FPFK081. Sheet code FPFK081, no revision or date printed; 2025 EZ111DV, EZ98DV and EZ71DV (GQ-...-FF-1 US); a service document filed under Field Manual in Noritz's Technical Literature; no page numbers printed, p. 1 is the PDF page. Accessed Oct 12, 2026.
  14. NORITZ America Corporation. EZ Technical Sheet FHCK080. Sheet code FHCK080, no revision or date printed; 2024 EZ111DV, EZ98DV and EZ71DV (GQ-...-FF US); a service document; no page numbers printed, p. 1 is the PDF page. Accessed Oct 12, 2026.
  15. NORITZ America Corporation. NRCP111/NRCP98 Technical Data Sheet Rev. 07/19. Rev. 07/19 (printed at the foot of p. 1); a service document filed under Field Manual; no page numbers printed, p. 2 is the PDF page. Accessed Oct 12, 2026.
  16. NORITZ America Corporation. Field Manual KS-11-0004. KS-11-0004, Rev. October 2012; cover title: Gas Water Heater Field Manual (NRC83, NRC98, NRC1111/NCC1991, NR981/NC199, NR83-DVC); written for service technician training seminars. Accessed Oct 12, 2026.
  17. NORITZ America Corporation. Field Manual June 2011. Rev. June 2011; cover title: Gas Water Heater Field Manual (NR50-OD, NR66, NR71, NR98, NCC199, NRC111, NR111, NC380); a service technician training document. Accessed Oct 12, 2026.
  18. NORITZ America Corporation. EZ Installation Manual Rev. 10/25. SBB81M3-1, Rev. 10/25; cover title: Condensing Tankless Gas Water Heater Installation Manual; covers EZ111DV, EZ98DV and EZ71DV (GQ-...-FF-1 US); linked from the EZTR50 and EZTR75 product pages, which the manual does not name. Accessed Oct 12, 2026.
  19. NORITZ America Corporation. EZTR40 Installation Manual Rev. 11/20. SBB809L-2, Rev. 11/20; covers NRC663-FSV (EZTR40), indoor installation; p. 22 is an image page without a text layer. Accessed Oct 12, 2026.