Have you ever jumped in the shower only to be greeted by a blast of cold water? If your Rheem gas water heater isn’t lighting, you’re not alone. Many homeowners face this frustrating issue, and it can feel overwhelming when you just want hot water.
Key Takeaways
- Common Ignition Issues: Familiarize yourself with pilot light and thermocouple problems that can prevent your Rheem gas water heater from lighting. Regular maintenance and checks can mitigate these issues.
- Troubleshooting Steps: Follow a systematic approach to identify problems, including checking the gas supply, pilot light, ignitor, and wiring to help restore functionality.
- Safety Precautions: Always ensure proper ventilation and disconnect power before performing any maintenance to minimize risks associated with gas appliances.
- Professional Help: Know when to call an expert. Persistent ignition issues, gas odors, electrical failures, or unusual noises warrant professional assessment to ensure safety and efficiency.
- User Manual Reference: Consult your water heater’s user manual for specific troubleshooting and operational guidelines tailored to your model, aiding in effective problem-solving.
Common Causes of Rheem Gas Water Heater Not Lighting
Several factors can prevent your Rheem gas water heater from lighting. Identifying these causes can simplify troubleshooting and repair.
Pilot Light Issues
Pilot light issues commonly lead to ignition failure. If the pilot light is out, it may have blown out due to drafts or improper maintenance. To relight it:
- Turn the gas control knob to “Off.”
- Wait a few minutes to clear any gas fumes.
- Switch the gas control knob to “Pilot.”
- Press the reset button while using a long lighter or match to ignite the pilot.
- Release the reset button once the pilot lights.
If the pilot light frequently goes out, you might need to check for obstructions, like dirt or debris, around the pilot assembly.
Thermocouple Problems
Thermocouple problems can also result in a non-lighting water heater. The thermocouple senses whether the pilot light is lit and controls the gas flow. If it’s faulty or disconnected, the gas supply will shut off.
To inspect it:
- Turn the gas control knob to “Off.”
- Disconnect the thermocouple from the gas control valve.
- Test it with a multimeter. Look for a resistance reading of about 30 millivolts.
- Replace a faulty thermocouple.
Ensure it’s tightly connected to prevent future problems. If replacing the part, follow manufacturer guidelines for installation.
Troubleshooting Steps
When your Rheem gas water heater won’t ignite, follow these troubleshooting steps to identify the problem and restore hot water.
Checking the Gas Supply
- Ensure Gas Valve is Open: Look for the gas valve on the supply line. It should be in the “On” position. If it’s closed, turn it to open it.
- Inspect for Gas Leaks: Apply a soapy water solution to all gas connections. Bubbles indicate a leak. If you find a leak, turn off the gas supply and seek assistance from a professional.
- Check Your Gas Supply: Ensure that the gas supply is active. Confirm this by checking if other gas appliances, like stoves or heaters, are igniting properly.
- Contact Your Gas Company: If other appliances are not working, contact your gas provider. They can assist with supply issues or outages.
- Examine the Pilot Light: Look for the pilot light at the bottom of the unit. If it’s out, follow the instructions for relighting.
- Check the Ignitor: Inspect the ignitor for proper function. If it doesn’t spark, it may require replacement.
- Inspect Wiring: Look at the wiring connected to the ignition system. Ensure no wires are frayed or loose. Repair or replace damaged wiring.
- Test the Thermocouple: The thermocouple senses flame presence. If it’s faulty, it can prevent ignition. Disconnect it and use a multimeter to check its resistance. If it’s outside the recommended range, replace it.
- Review User Manual: Your unit’s manual often contains specific troubleshooting and operational tips. Refer to it for guidance tailored to your model.
Following these steps helps identify issues affecting your Rheem gas water heater’s ignition. With careful inspection and maintenance, you can restore its functionality effectively.
Safety Precautions
Safety is paramount when dealing with gas water heaters. Following proper precautions minimizes risks and ensures efficient operation.
Ensuring Proper Ventilation
Ensure adequate ventilation in the area surrounding your Rheem gas water heater. Proper airflow prevents harmful gas buildup. Maintain clearances around the heater by keeping vents unobstructed. Open windows or use exhaust fans to promote airflow, especially during troubleshooting or maintenance. Regularly check the vent pipes for blockages or corrosion to ensure safe exhaust.
Disconnecting Power Before Maintenance
Disconnect power before performing any maintenance on your water heater. Turn off the gas supply and unplug the heater to prevent accidental ignition. Use a wrench to close the gas valve securely. Double-check that the power is off to avoid electrical hazards while inspecting components. These simple steps significantly enhance your safety during troubleshooting and repairs.
When to Call a Professional
Recognizing when to seek help from a professional can save time and prevent further damage to your Rheem gas water heater. Consider contacting a licensed technician in the following scenarios:
Persistent Ignition Issues
If your water heater doesn’t light after several attempts, this signals a more significant problem. A technician can diagnose issues with the gas supply or components.
Gas Smells
Never ignore the smell of gas. If you detect a gas odor, turn off the gas supply immediately. Contact a qualified professional for prompt assistance.
Electrical Problems
If the ignitor fails to spark despite a functional gas supply, the wiring or ignitor itself may be damaged. An expert can safely inspect and replace these parts.
Thermocouple Malfunctions
Failure to maintain a steady pilot light might point to a faulty thermocouple. A technician can evaluate this component and replace it if necessary.
Lack of Hot Water
If your heater doesn’t provide hot water, troubleshooting might not resolve the issue. A professional can evaluate the entire system to identify the root cause.
Unusual Noises
Strange noises from the heater may indicate problems with internal components. A technician’s assessment can uncover underlying issues, ensuring your safety and system longevity.
Safety Concerns
If you feel uncertain about performing any repairs or maintenance, it’s best to call a professional. Prioritizing your safety ensures that you’re not risking accidents while troubleshooting the heater.
By seeking help when needed, you can ensure your Rheem gas water heater operates efficiently and safely.
Conclusion
Dealing with a Rheem gas water heater that won’t light can be frustrating but you’re not alone. By following the troubleshooting steps outlined in this article you can often identify and fix the issue yourself. Remember to prioritize safety throughout the process and don’t hesitate to reach out to a professional if you’re unsure or if problems persist. Keeping your water heater well-maintained will help ensure you enjoy hot showers without interruption. With a little patience and care you’ll have your hot water back in no time.
Frequently Asked Questions
What causes Rheem gas water heaters to not ignite?
The main causes of ignition failure in Rheem gas water heaters include a malfunctioning pilot light, faulty thermocouple, closed gas valve, or gas leaks. Issues with the ignitor and wiring can also lead to ignition problems.
How can I relight the pilot light on my Rheem gas water heater?
To relight the pilot light, first, turn off the gas valve and wait a few minutes. Then, follow your user manual’s specific instructions for igniting the pilot light, usually involving pressing a reset button while holding a lit match or lighter to the pilot.
What should I check if my gas water heater flame goes out?
If the flame goes out, check the gas valve to ensure it’s open, inspect for gas leaks, and examine the pilot light assembly. Additionally, assess the thermocouple for proper function, and ensure that the ignitor is working.
When should I call a professional for my Rheem gas water heater?
You should call a professional if you detect gas odors, experience persistent ignition issues, hear unusual noises, or notice electrical problems. If there’s a lack of hot water or if you find a malfunctioning thermocouple, professional help is advised.
Are there safety precautions I should follow when troubleshooting my water heater?
Yes! Always ensure proper ventilation around your gas water heater and maintain clearances. Disconnect power and turn off the gas supply before performing any maintenance to prevent gas leaks and electrical hazards.
How do I test the thermocouple on my gas water heater?
To test the thermocouple, use a multimeter set to measure resistance. Disconnect it from the gas valve and check for continuity. If there’s no reading or it’s outside the normal range, the thermocouple may need replacement.
What maintenance can I do to prevent ignition issues with my gas water heater?
Regularly inspect the pilot light assembly and thermocouple, check for gas leaks, and ensure the gas valve is working properly. Additionally, keep the area around the heater clear of debris and ensure it has adequate ventilation.

Jake Newman is Appliance Mastery’s expert on refrigeration and cooling systems. With over a decade of experience in the appliance repair industry and certification from NASTeC, Jake is a trusted source of knowledge for homeowners who want to troubleshoot and repair their fridges, freezers, and air conditioning units.