Is your Rheem tankless water heater showing a Code 12 error? This can be frustrating, especially when you rely on your hot water daily.
But don’t worry—you can troubleshoot and fix this issue without waiting for a costly technician. Code 12 usually points to a flame failure, which means your water heater isn’t igniting properly. In this guide, you’ll learn simple, clear steps to identify the cause and get your heater back to working smoothly.
Keep reading, and you’ll be able to enjoy hot water again in no time.
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Error Code 12 Explained
Error Code 12 on a Rheem tankless water heater signals an ignition failure. This means the heater tries to light but does not create or hold a flame. The code acts as a warning to check the ignition system and gas supply. Understanding this code helps in quick diagnosis and repair. It prevents further damage and restores hot water supply efficiently.
Common Causes
Ignition failure often results from several common issues. A blocked gas valve can stop gas flow to the burner. Dirty or faulty igniters can fail to spark properly. Flame sensors may get coated with dirt, causing false flame detection. Air intake or exhaust vents can become clogged, restricting air needed for combustion. Low gas pressure is another frequent cause of this error code.
Impact On Heater Performance
Error Code 12 directly affects the water heater’s operation. Without ignition, the unit cannot heat water. This leads to no hot water supply in your home. The heater may also shut down as a safety precaution. Persistent ignition problems can cause the system to wear out faster. Addressing the error quickly ensures steady performance and extends heater life.
Check Gas Supply
Checking the gas supply is a key step in fixing Rheem tankless water heater code 12. The error often means the heater is not getting enough gas. This can stop the unit from lighting or cause the flame to go out. Confirming a proper gas supply helps avoid bigger problems and keeps your heater running smoothly.
Start by verifying that the gas valve is open. Then inspect the gas line for any blockages. These simple checks can solve many gas-related issues that cause error code 12.
Ensure Gas Valve Is Open
Locate the gas valve near your water heater. It usually has a handle that controls gas flow. The valve must be fully open for gas to reach the unit. Check that the handle is parallel to the gas pipe. If it is perpendicular, the valve is closed. Open it by turning the handle 90 degrees. This step ensures gas can flow freely to the heater.
Inspect Gas Line For Blockages
Look along the gas line for any signs of damage or obstruction. Dirt, debris, or pests can block the line and reduce gas flow. Clear any visible blockages carefully. Check for kinks or bends that might restrict gas. Also, ensure the line is connected securely with no leaks. A blocked gas line can starve the heater of gas, causing error code 12. Fixing blockages restores proper gas pressure for reliable ignition.
Inspect Air And Exhaust Vents
Inspecting the air and exhaust vents is crucial when fixing Rheem tankless water heater code 12. Blocked or damaged vents can stop proper airflow. This disrupts combustion and causes error codes. Regular vent checks help maintain heater efficiency and safety.
Air intake vents bring fresh air for combustion. Exhaust vents remove harmful gases safely outside. Both must stay clear and undamaged for the heater to work well. Neglecting these vents often leads to code 12 errors and poor performance.
Clear Vent Obstructions
Check both air intake and exhaust vents for debris or blockages. Leaves, dirt, or bird nests can clog the vents. Use a soft brush or vacuum to remove dirt carefully. Avoid pushing debris further inside the vent.
Inspect vent covers and screens. Replace damaged or missing parts to keep pests out. Ensure vents have no dents or cracks that limit airflow. Clear vents improve combustion and stop error codes.
Prevent Freezing In Cold Weather
Cold weather can freeze vent pipes and block airflow. Insulate vent pipes with foam sleeves or heat tape. Keep the area around vents free from snow and ice build-up. Check vents regularly during winter months.
Install a vent cover designed for winter protection. It stops ice from forming inside the vent. Preventing freezing reduces code 12 errors and keeps your water heater running smoothly.
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Clean Igniter And Flame Sensor
Cleaning the igniter and flame sensor is a key step to fix Rheem tankless water heater code 12. These components help the heater detect and maintain the flame. Dirt or buildup can stop them from working properly. Regular cleaning keeps your heater running smoothly and avoids error codes.
Turn Off Power And Remove Cover
First, turn off the power to the water heater. This keeps you safe while working. Next, use a screwdriver to remove the front cover. Set the screws aside carefully. This exposes the igniter and flame sensor inside the unit.
Remove Dirt And Debris
Use a soft cloth or fine sandpaper to clean the igniter and flame sensor gently. Remove any dirt, dust, or soot buildup. Avoid using water or harsh cleaners. Clean parts improve flame detection and prevent error code 12 from appearing.
Check Wiring Connections
Look at the wiring connected to the flame sensor and igniter. Make sure all wires are tight and secure. Look for any signs of damage or corrosion. Loose or damaged wires can cause the heater to malfunction. Fix any wiring issues before reassembling the unit.
Replace Faulty Components
Replacing faulty components is a key step in fixing Rheem Tankless Water Heater Code 12. This error often points to problems with ignition or flame detection parts. Swapping out damaged parts can restore your heater’s function and safety quickly. Focus on the igniter, flame sensor, and gaskets for best results.
Igniter Replacement
The igniter lights the burner inside the water heater. A faulty igniter stops the flame from starting. Turn off power and gas before replacing it. Remove the front panel to access the igniter. Disconnect the wiring and unscrew the old igniter. Install the new igniter and reconnect wiring. Replace the panel and test the heater.
Flame Sensor Replacement
The flame sensor detects if the burner flame is on. A dirty or broken sensor causes the heater to shut down. Power off the unit to stay safe. Open the front cover and find the sensor near the burner. Unscrew the sensor and unplug the wires. Insert the new sensor and reconnect wires. Close the panel and power the heater back on.
Gasket Inspection And Replacement
Gaskets seal parts of the heater to prevent leaks and maintain pressure. Worn or damaged gaskets can cause errors. Inspect gaskets around the burner and heat exchanger. Look for cracks or breaks. Remove any faulty gaskets carefully. Fit new gaskets in place. Ensure a tight seal before reassembling the heater. Check the unit for leaks after replacement.
Resetting The Water Heater
Resetting the Rheem tankless water heater is a key step to fix Code 12 errors. This error often signals a problem with the ignition or flame detection system. Resetting the unit can clear minor faults and restore normal operation. Follow simple reset methods carefully for safety and effectiveness.
Power Cycle Steps
Start by turning off the power supply to the water heater. Locate the circuit breaker and switch it off. Wait for about 5 minutes to let the system fully power down. This pause helps clear temporary glitches in the electronics.
After waiting, switch the circuit breaker back on. This action restarts the control board and resets error codes. Check the display for any remaining error messages. If Code 12 still shows, try the manual reset button next.
Using The Reset Button
Find the reset button on the front panel of the water heater. It is usually a small, red or black button. Press and hold the button for about 3 seconds. Release it and watch the display for changes.
The reset button forces the unit to restart its ignition sequence. If the error clears, the heater should start heating water normally. If the error persists, further inspection or professional help may be needed.
When To Call A Technician
Knowing when to call a technician for Rheem tankless water heater code 12 is key. Some problems need expert skills and tools. Calling a professional can save time and prevent further damage. It also keeps you safe from risks related to gas and electrical parts.
Gas Supply Issues
Gas supply problems can cause code 12 errors. A technician checks gas pressure and flow accurately. They find hidden leaks or blockages in the line. Adjusting gas valves requires special tools and knowledge. Incorrect handling can cause gas leaks or fire hazards.
Complex Repairs
Some repairs are too complex for homeowners. Problems with the igniter, flame sensor, or control board need expert care. Technicians have training to diagnose and fix these parts. They use proper replacement parts to ensure long-term function. DIY fixes might worsen the issue or void warranties.
Safety Precautions
Working on gas appliances is risky without training. A professional follows strict safety rules to avoid accidents. They turn off gas and power before starting repairs. Proper ventilation checks prevent carbon monoxide buildup. Calling a technician protects your home and health.
Preventive Maintenance Tips
Preventive maintenance keeps your Rheem tankless water heater running smoothly. It helps avoid Code 12 errors and extends the heater’s life. Simple regular care catches problems early. Follow these tips to maintain your unit effectively.
Regular Cleaning Schedule
Clean your water heater every 6 to 12 months. Remove dust and debris from vents and air intakes. Wipe down the exterior to prevent dirt buildup. Use a soft cloth and mild detergent. Cleaning stops blockages that cause error codes and poor performance.
Seasonal Checks
Inspect the water heater before winter and summer. Check for frozen or blocked vents during cold months. Look for leaks or rust around pipes and fittings. Test water temperature and pressure regularly. Seasonal checks help spot issues early and keep the heater safe.
Monitoring Error Codes
Watch the display panel for error codes like Code 12. Note any recurring errors and their timing. Reset the unit if needed, but do not ignore repeated codes. Keeping track helps you act before small problems become big. Addressing errors early saves time and money.
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Frequently Asked Questions
How To Fix Code 12 On Tankless Water Heater?
Turn off power to the heater. Check gas valve is fully open and vents are clear. Clean or replace igniter and flame sensor. Inspect wiring for damage. Restore power and test. Call a technician if the error persists or for gas supply issues.
How Do I Fix Error Code 12 On Rheem?
Turn off power to the Rheem unit. Check gas valve is fully open and vents are clear. Clean or replace igniter and flame sensor. Inspect wiring for damage or looseness. Restore power and test. Call a technician if the error persists or for gas supply issues.
What Does Code 12 Mean?
Code 12 usually indicates a flame failure or ignition problem in tankless water heaters. Check gas supply, vents, and flame sensor for issues.
How Do You Reset The Error Code On A Rheem Tankless Water Heater?
Turn off the power to the Rheem tankless water heater. Press and hold the reset button for 5 seconds. Release it and restore power. Check if the error code clears. Contact a technician if the error persists.
What Does Rheem Tankless Water Heater Code 12 Mean?
Code 12 means the flame failed to ignite or stay lit in your heater.
Conclusion
Fixing Rheem tankless water heater code 12 is often simple. Start by checking the gas supply and vents for blockages. Clean the igniter and flame sensor carefully. Make sure all wiring is secure and undamaged. If problems continue, replacing faulty parts may help.
Always turn off power before working on the unit. Safety matters most during any repair. When unsure, call a professional technician for help. Following these steps can restore your water heater’s function quickly and safely.