{"id":116,"date":"2021-04-12T21:19:20","date_gmt":"2021-04-12T21:19:20","guid":{"rendered":"https:\/\/knowall.dev19.bigideas.io\/?post_type=ht_kb&p=116"},"modified":"2023-06-13T23:19:52","modified_gmt":"2023-06-13T23:19:52","slug":"errorcode12","status":"publish","type":"ht_kb","link":"https:\/\/help.noritz.com\/index.php\/knowledge-base\/errorcode12\/","title":{"rendered":"Error Code 12"},"content":{"rendered":"\n

EC 12, or Error Code 12<\/strong><\/p>\n\n\n\n

An error code 12 indicates a flame loss. This means that the unit is detecting a flame, but the flame is being extinguished during operation (weak flame).
 
Most of the same troubleshooting used in the Error Code 11<\/a> article can be applied to the error code 12 such as cleaning the flame rod and making sure the unit has sufficient gas to ignite and stay lit. Additionally improper venting could be a cause especially if the unit is Direct Vented (DV) and the air intake is drawing in the exhaust of the unit or another gas burning appliance.<\/p>\n\n\n\n

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Examples of incorrect venting that could cause the 12 error code among other problems.<\/figcaption><\/figure>\n\n\n\n

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Specific to our Direct Vent Concentric (DVC) models, if the incorrect type of vent is used you will get 12 codes, combustion noises and other issues. Concentric venting is a pipe within a pipe style and it’s used to provide the ease of installing like a Single Vent (SV) unit with just one penetration through the building but providing the benefits of a DV install.<\/p>\n\n\n\n

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DVC pipe. Inner 3″ pipe handles exhaust, outer 5″ pipe handles air intake.<\/figcaption><\/figure>\n\n\n\n

NR83DVC and NR98DVC models require the use of Noritz Concentric Venting<\/a>. There are o-rings on the smaller 3″ exhaust venting meant to keep the seal 100% air tight and prevent it from leaking exhaust into the air intake side. If those o-rings are missing or damaged the unit could give 12 codes or other noises.<\/p>\n\n\n\n

Inlet gas pressure could be an issue. When testing inlet gas pressures we recommend 3 different tests:<\/p>\n\n\n\n

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  1. Static Test<\/strong>. This is the inlet gas pressure at the unit when no gas is being used.<\/li>\n\n\n\n
  2. Dynamic Test<\/strong>. This is the inlet gas pressure at the unit when it’s fired up and heating water.<\/li>\n\n\n\n
  3. Max Dynamic Test<\/strong>. This is the inlet gas pressure at the unit when it’s fired up with a high demand and other gas appliances are used (furnace, oven, etc).<\/li>\n<\/ol>\n\n\n\n

    Under all 3 tests the inlet gas pressure to the unit should always be above the minimum required gas pressure as stated on the unit.<\/p>\n\n\n\n

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    Inlet gas pressure specs on the rating plate. Natural Gas (NG) and Liquid Propane (LP) will have different specs.<\/figcaption><\/figure>\n\n\n\n

    If the inlet gas pressure drops below the minimum rating of the unit, there is an issue in the gas supply that needs to be addressed for the unit to work properly under all conditions.<\/p>\n\n\n\n

    For California installations there is likely an earthquake safety shut off on the gas line near the meter that may have been tripped during an earthquake or other bump or vibration. Follow the proper reset procedure based on the shut off you have, it’s usually labelled on the device itself.<\/p>\n\n\n\n

    Troubleshooting gas issues should be left to a professional as there is some serious risk if you\u2019re unfamiliar with what you\u2019re doing.<\/p>\n\n\n\n

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