Posted on Feb 10, 2022 | 3 comments

Typically error code 11 for the Rinnai tankless signals there is NO IGNITION

The Rinnai tankless error code 11 can be a bit of a tricky error to diagnose as there can be a lot of different causes. Below we have gone through and listed a troubleshooting process map to help you narrow down where the error could be coming from.

If you are not a professional or do not feel comfortable taking apart and fixing items you should call a registered repair person to fix this error. There are explosive gases inside a Rinnai tankless system that can be very dangerous if you are not knowledgeable and experienced.

Start With Step One To Repair Your Rinnai Tankless Error Code 11

1. Verify all gas valves on gas system are open feeding the proper gas pressure to said appliance.
2. Check all air was purged from gas lines after installation.
3. Verify proper inlet gas pressures are being fed to appliance. Check appliances rating plate for proper
   pressures. This plate or label is located on the side of each unit. The minimum listed inlet pressure MUST be maintained with all gas appliances at the location firing on high fire. If the product is a condensing unit the front panel must be installed before testing inlet pressures.
4. Verify proper gas type; ensure the gas supply at this location matches that listed on said appliance.
5. Verify gas type dip switch on PC board is switch to proper gas type position.
6. Verify igniter is working. Turn off gas valve feeding the appliance. Unplug igniter wire; hold the igniter wire with an insulated pair of pliers about a 1/4″ from a piece of metal. Cycle the unit to ensure you see a spark when unit is cycling. If not, check ignition system for loose connections, damaged components or disconnected plugs back to PC board. . If no spark is noted check the ignition board to verify it is getting the proper voltage from the PC board. See troubleshooting document under the unit’s front cover for proper voltage and connector numbers. Note; there will be no voltage present unless the unit is going through the ignition cycle.
7. Make sure the ceramic sparker electrode is tight in its mounting bracket. You should not be able to
   move it with your finger if gasket is intact. If loose remove it and clean with dollar bill. Reinstall using
   new gasket and ensure it is tight when the installation is finished. If the electrode is loose the tip can
   drop down and touch the burners creating a short or no spark. A loose flame rod is called a floating
   flame rod and will result in code 11’s or 12’s.
8. Verify the proper flame rod wire is plugged into the proper flame rod. Some units have multiple flame rods. A quick check to verify correct wiring is to look at the stamped letter on the bracket at flame rod, sample a Y indicates yellow, R = red and B = blue
9. Verify the flame rod is tight in its mounting bracket. You should not be able to move it with your
   finger if gasket is intact. If loose remove it and clean with dollar bill. Inspect flame rod for cracks.
   Reinstall using new gasket and ensure it is tight when installation is finished. A loose flame rod is called a floating flame rod and will result in code 11’s.
10. Look into view window on appliance to see if you ever see a flame in the burner box while the unit is
    going through the ignition cycle. If you do that indicates an issue in the flame rectification circuit. This could be a buildup of carbon or a white substance on flame rod, bad connection at flame rod, loose or damaged flame rod, bad PC board, gas valve or low inlet gas pressures. Before replacing the PC board or gas valve continue troubleshooting the steps below.
11. Remove igniter and flame rod and inspect them for carbon or a white substance build‐up. Clean both the igniter and flame rod before reinstalling. In addition inspect the burners under the igniter for condensate build‐up or debris. Blow out burners and burner box with 120 psi of air. If you remove just the igniter and flame rod assemblies, make sure you have a new flame rod/igniter gasket. This gasket MUST be replaced if this seal is broken. While inside the burner box look up between the copper fins inside the heat exchanger for debris and/or blockage. Blow out fins, if unable to clean out fins inside combustion box replace heat exchanger.
12. If you note improper inlet gas pressures check to see if the gas system was properly sized. If sized
    properly you should see no more than a 0.3 inch pressure drop on natural gas with all gas appliances in the building firing on high fire. The allowable pressure drop for propane is 0.5 inches of water column. This pressure drop is based on the International Plumbing Code when operating on gas pressures up to
    14″ inches W.C. with black iron piping. There are a number of approved gas piping system out there,
    make sure you refer to the manufacture’s or International Plumbing Code book for pressure drops on gas piping and pressures you are using for proper pressure drops allowed. If pressure drop excesses that mentioned above for black iron gas systems, your system could be undersized, please recheck sizing. The issue could be in any of the following items; the gas system, gas piping, regulator, tank, utility supply, dirt or debris in gas system components, etc. Have the gas system checked by a professional gas technical or master plumber that deals with gas system sizing. Refer to the International Plumbing Code Book for proper gas system sizing for gas type, piping and pressures being used at this location.
13. Inspect vent system for loose joints, improper fittings, failure to meet clearances around vent
    terminal outside building. See venting instructions for clearance specifications. Failure to meet vent
    terminal clearances can lead to recirculation of combustion gases causing incomplete combustion which will lead to carbon build up on flame rod. In addition; ensure vent length is within specifications and dip switch for vent lengths has been properly set.
14. Verify installer used the proper venting materials for the unit at your location. They must use the
    correct venting material for class III appliances approved by Rinnai. See Rinnai venting instructions for details.
15. Verify proper altitude settings, see high altitude gas pressure setting procedure for dip switch and
    manifold gas pressure settings.
16. On internal units inspect the plastic tube running from the bottom of the combustion chamber to
    the gas valve. If you find moisture in that tube, replace the gas valve. Also inspect the vent system to see where the condensate/moisture is coming from. The burner and heat exchanger fins should be
    inspected for excessive corrosion also. Signs of moisture could be a result of an improper venting or a leak inside the heat exchange.
17. Verify installer used the condensate drain tap as recommended by Rinnai on the vent terminal
    connection at the top of the water heater, non‐condensing product. If the condensate drain line is not connected please install one per Rinnai venting instructions. If a condensate line is in use, inspect the vent connector on top of water heater to ensure it’s not stopped up. In addition; check the condensate drain trap and line for blockage. If stopped up remove vent pipe from unit and clean out all debris and/or build up from the trap or line.
18. Check to ensure all two stages regulators are installed at least six foot away from appliance. Ensure
    when appliance shuts off the pressure from the two stage regulator doesn’t exceed the maximum inlet pressure for the appliance. To verify this connect your manometer up to the test port on the bottom of the water heater. The inlet pressures should never exceed 10 inches water column for natural gas or 13.5 inches on propane. If it does the regulator may be defective.
19. Inspect all wiring harnesses throughout unit for water or moisture in electrical connections. If any
    connections appear to be damp or wet dry them out and try to find out what is causing this.
20. If using an MSA or MSB system isolate the unit giving trouble from the system during
    troubleshooting. If unit operates when isolated the issue may be in the electronic staging system (MSA or MSB).
21. Other suggestions;
    a. Verify spark electrode is installed in the correct position.
    b. Verify all burner cassettes are in place in burner rack. Sometimes when contractors drop a unit the
    burners can shift and become dislodged. If you find the burners dislodged loose burner bracket and
    reseat them.
    c. Remove the four burners located under the flame rod and move them over to the high fire side of
    the burner tray. Move the four burners from the high fire side over under the flame rod. Sometimes
    condensate or debris can get down in the burners and cause turbulence inside the burner.
    d. Condensate, debris or a malfunctioning mechanical component inside the gas valve may be
    preventing the valve from opening correctly once in a while. Replace gas valve.
    e. Voltage output to gas valve from PC board could be incorrect or intermittent due to a bad
    component on PC board, replace PC board.

For All Other Rinnai Error Codes See Below