Atwood Furnace Troubleshooting⁚ Common Issues
This guide addresses common Atwood furnace problems. No heat with the blower running suggests a gas supply, ignition, or sensor issue. Ignition failure points to a faulty spark igniter, flame sensor, or control board. A malfunctioning blower motor requires motor or wiring checks. Consult your model’s specific troubleshooting guide for detailed steps.
No Heat, Blower Runs
If your Atwood furnace blower operates but produces no heat, several potential problems exist. First, verify adequate propane supply; check the tank level and ensure the gas valve is open. Inspect the gas line for any kinks or blockages that might restrict gas flow to the furnace. A faulty flame sensor can prevent ignition even with sufficient gas; a dirty sensor may need cleaning, while a damaged one requires replacement. The igniter, responsible for sparking the gas, should also be examined; a weak or broken igniter will fail to ignite the propane. The sail switch, a safety device that ensures proper airflow, may be stuck or malfunctioning, preventing the furnace from starting. Finally, a problematic control board might not send the necessary signals for ignition. If these checks yield no results, professional assistance may be required.
Ignition Problems⁚ No Spark or Flame
When your Atwood furnace fails to ignite, the problem could stem from several components. The igniter, responsible for creating the spark that ignites the propane, is a prime suspect. A faulty igniter might be weak, producing insufficient spark, or completely broken, requiring replacement. The flame sensor, detecting the presence of the flame, plays a crucial role in the ignition process. If it’s dirty, it may fail to sense the flame, causing the furnace to shut down. Clean the sensor carefully; if the problem persists, replacement might be necessary. Ensure the control board, which governs the entire furnace operation, is functioning correctly. A malfunctioning control board can prevent the igniter from sparking or the gas valve from opening. Check the wiring connections to the igniter and flame sensor for any loose or corroded connections. Lastly, inadequate gas supply can also lead to ignition failure; verify the propane tank level and the gas valve’s proper operation.
Blower Motor Malfunctions
A non-functional blower motor prevents the circulation of heated air, a critical aspect of your Atwood furnace’s operation. First, inspect the blower motor itself for any visible damage, such as loose wires, burned-out components, or physical obstructions. Check the motor’s power supply; a faulty power connection will render the motor inoperable. Verify the continuity of the wiring leading to the motor using a multimeter. If the wiring is intact, the issue might be within the motor’s internal components. A faulty capacitor, a common culprit in blower motor failures, might require replacement. Examine the motor’s bearings for wear and tear; excessive noise or roughness can indicate worn bearings. Replacing the bearings might restore functionality. The blower motor’s speed control mechanism could also be at fault. If the motor runs too slowly or not at all, check the control circuit for any issues. Consult your furnace’s wiring diagram for troubleshooting guidance; this will help locate specific components and their functions. If all else fails, replacing the blower motor might be the solution.
Diagnosing Atwood Furnace Problems
Systematic troubleshooting is crucial. Check gas supply, inspect the flame sensor and igniter for proper function, and test the sail switch and limit switch operation. These initial checks often pinpoint the problem’s root cause.
Checking Gas Supply and Pressure
Before assuming a furnace malfunction, verify adequate gas supply. Begin by ensuring your propane tank valve is fully open and contains sufficient propane. Check for any visible leaks around the tank, regulator, and supply lines using soapy water; bubbling indicates a leak requiring immediate attention. A low-pressure situation can prevent ignition. Use a pressure gauge to measure the gas pressure at the furnace connection point. Consult your furnace’s manual for the specified operating pressure range. If the pressure is too low, check the regulator for proper function and consider replacing it if necessary. A clogged gas filter or a kinked supply line can also restrict gas flow, so inspect these components carefully. If all connections are secure and pressure is within the normal range, proceed to check other furnace components. Remember safety first and always turn off the gas supply before performing any repairs or inspections.
Inspecting the Flame Sensor and Igniter
The flame sensor and igniter are crucial for ignition. The flame sensor, a small, rod-like component, detects the presence of a flame. Soot buildup can interfere with its operation. Carefully clean the sensor with fine-grit sandpaper or a wire brush, ensuring not to damage its surface. A dirty sensor might prevent the furnace from detecting the flame, leading to shutdowns. The igniter, typically a glow bar or electrode, generates a spark to ignite the gas. Visually inspect it for damage or cracks. A faulty igniter won’t produce a spark, preventing ignition. If the igniter is damaged, it will need replacement. Access to these components varies by model; refer to your furnace’s service manual for specific instructions and safety precautions. Always disconnect the power supply before handling these electrical components. After cleaning or replacing parts, reconnect and test the furnace. If issues persist, further troubleshooting is needed.
Testing the Sail Switch and Limit Switch
The sail switch and limit switch are safety devices preventing furnace operation under unsafe conditions. The sail switch, a small, often overlooked component, confirms that the blower is running before ignition. A faulty sail switch will prevent the furnace from starting, even if everything else is functional. To test it, visually inspect for obstructions or damage. Gently actuate the switch lever; you should hear a distinct click. If not, the switch may need replacement. The limit switch prevents overheating. Located near the heat exchanger, it cuts power if the furnace gets too hot. Testing involves checking for continuity using a multimeter. With the furnace off, disconnect the limit switch wires and test for continuity across the terminals. If there’s no continuity, the switch is faulty and needs replacing. Always consult your model’s service manual for switch locations and testing procedures. Replace faulty switches to restore safe and proper furnace operation. Incorrectly functioning limit switches can lead to overheating and potential fire hazards.
Advanced Troubleshooting Steps
For persistent issues, examine the control board and wiring for damage or loose connections. Inspect the thermocouple for proper function and the exhaust system for blockages. These steps require more technical expertise; consult a professional if unsure.
Examining the Control Board and Wiring
The control board is the furnace’s “brain,” managing gas flow, ignition, and the blower; Carefully inspect the board for any visible damage, such as burnt components, cracked solder joints, or corrosion. Look for any signs of overheating or unusual discoloration. A magnifying glass can help in this inspection. Next, check all wiring connections to and from the control board. Loose connections or corroded wires can interrupt signals and prevent the furnace from working correctly. Use a multimeter to test continuity and voltage at various points if necessary. Ensure all wires are securely fastened and free of damage. If you find any issues, carefully repair or replace the damaged components, following the manufacturer’s instructions or seeking professional assistance. Do not attempt repairs if you are not comfortable working with electrical components.
Troubleshooting the Thermocouple
The thermocouple is a safety device crucial for Atwood furnace operation. It’s a temperature sensor that generates a small voltage when heated by the pilot flame; This voltage signal tells the control board that the flame is present, allowing the furnace to continue operating. A faulty thermocouple can prevent the furnace from igniting or cause it to shut down intermittently. To troubleshoot, carefully inspect the thermocouple for any physical damage, such as cracks or bends; A multimeter can test its voltage output; a reading near zero volts indicates a problem. If the thermocouple is damaged or not producing the correct voltage, it needs replacement. Remember to always disconnect the gas supply before working with the thermocouple or any other gas-related components. Incorrect handling can lead to gas leaks and safety hazards. Consult your furnace’s specific manual for detailed instructions on thermocouple testing and replacement.
Assessing Exhaust System Blockages
A blocked exhaust system is a serious safety hazard with Atwood furnaces, potentially leading to carbon monoxide buildup. Regular inspection is vital. The exhaust vent should be clear of debris, such as leaves, insects’ nests, or snow. A visual inspection from outside the RV should reveal any obvious blockages. A small mirror or flashlight might aid in examining hard-to-reach areas. If the vent appears obstructed, carefully remove any debris. Never use excessive force, as this could damage the exhaust system. If the blockage persists or is internal, professional assistance is recommended. A clogged exhaust system can also be indicated by unusual noises during furnace operation or a failure to ignite. Always ensure proper ventilation in your RV, even with a seemingly functional exhaust system. Carbon monoxide detectors are essential safety devices for RVs and should be regularly tested and maintained.
Atwood Furnace Models and Specific Issues
Atwood produces various furnace models, each with unique features and potential problems. Consult your specific model’s manual for detailed troubleshooting and repair information. Online forums and resources offer additional support for model-specific issues.
Model-Specific Troubleshooting Guides
Accessing model-specific troubleshooting guides is crucial for effective Atwood furnace repair. These guides provide detailed diagrams, component locations, and step-by-step instructions tailored to your exact furnace model (e.g., Atwood 8500 series, Atwood 79 series, Atwood 8000-II). They often include error code decipherment, helping you pinpoint the problem area. Remember to always consult your owner’s manual first for safety precautions and initial checks before attempting any repairs. Many online forums and RV repair websites offer model-specific troubleshooting tips and advice from experienced users and technicians. These resources can be invaluable when dealing with unusual or persistent problems. Searching for “[your model number] Atwood furnace troubleshooting” usually yields relevant results. If you’re still stuck, consider contacting Atwood customer service or a qualified RV technician for professional assistance. They can provide expert guidance and ensure the repair is done safely and correctly.