The Atwood furnace reset switch is a small but critical safety device in RV and marine heating systems, designed to protect the furnace from overheating and electrical faults. This guide explains how to locate the reset switch, recognize symptoms of a faulty switch, safely test it, and replace it with the correct parts. It focuses on practical troubleshooting and maintenance tips for American users while highlighting compatibility, safety, and when to call a professional.
| Issue | Likely Cause | Quick Fix |
|---|---|---|
| Furnace Won’t Turn On | Tripped Reset Switch, Blown Fuse | Check/reset switch, replace fuse |
| Furnace Starts Then Shuts Off | Overheat, Faulty Switch, Blocked Vent | Clear vents, test switch, inspect heat exchanger |
| Intermittent Operation | Loose Wiring, Weak Switch | Tighten connections, test continuity |
What The Atwood Furnace Reset Switch Does
The Atwood furnace reset switch is a manual or automatic thermal safety device that interrupts power when the furnace overheats or when an electrical fault is detected. Its primary role is to prevent fire and component damage by cutting power to the blower or combustion system until the condition is resolved and the switch is reset or replaced.
Common Models And Compatibility
Atwood furnaces are sold under various model names including Atwood, Suburban (older overlap), and Dometic-acquired lines. Reset switches and thermostats vary by model. Before replacing a switch, verify the furnace model number and part number, which are usually located on the furnace access panel or the data plate on the exterior of the unit.
Typical Part Numbers And Types
Common reset switch part types include push-button thermal resets and small snap-action switches used on blower motor circuits. Typical part numbers vary by furnace series; OEM Atwood part numbers or compatible replacements from Dometic are recommended. Aftermarket parts can work but verify voltage, amp rating, and mounting style match the original.
Symptoms Of A Faulty Reset Switch
Recognizing symptoms helps avoid unnecessary disassembly. Common signs include: complete power loss to the furnace, intermittent operation, furnace starts then stops, or a switch that won’t reset. Some faults mimic thermostat, battery, or control board issues, so systematic troubleshooting is essential.
Safety Precautions Before Working On The Furnace
Always disconnect power sources before inspecting or replacing the reset switch. Remove 12V battery power and disconnect shore power or the RV’s main battery as applicable. Wear insulated gloves, use eye protection, and ensure the furnace is cool to avoid burns. If unfamiliar with electrical systems, seek a qualified RV technician.
How To Locate The Atwood Furnace Reset Switch
The reset switch is typically mounted near the blower motor or on the furnace housing inside the access panel. On many Atwood units it is a small, recessed button labeled “Reset” or a small rectangular switch near the main wiring harness. Consult the furnace wiring diagram on the furnace door or owner’s manual for the exact location.
Step-By-Step Location Tips
Step 1: Remove the furnace access panel by unscrewing or releasing the latch. Step 2: Look along the blower housing or near the control module for a small push button or plastic housing. Step 3: Trace the wiring from the transformer or blower motor; the reset switch is usually inline with these circuits.
Tools And Materials Needed
A simple toolkit covers most tasks: insulated screwdrivers, socket set, needle-nose pliers, multimeter, replacement reset switch (OEM recommended), electrical tape, small wire crimper, and dielectric grease. For soldered connections, a soldering iron and heat-shrink tubing are helpful.
How To Test The Reset Switch
Testing confirms whether the reset switch is the cause. First, perform a visual inspection for corrosion, melted housing, or loose connections. Second, use a multimeter to test continuity. If the switch is a push-button type, it should show continuity when engaged and open when not reset.
Continuity Test Procedure
Step 1: Disconnect furnace power. Step 2: Remove wires from the switch terminals or access the connector. Step 3: Set the multimeter to continuity or the lowest ohms setting. Step 4: Press the reset button while measuring; the meter should read near-zero ohms when reset and infinite when tripped. Replace the switch if readings are inconsistent.
Testing With Power Safely
Only qualified individuals should energize the furnace for live testing. With power applied cautiously and proper PPE, measure voltage across the switch terminals when the system should be on. Expect nominal 12V DC in most RV furnaces. If voltage is present but the circuit is open through the switch, replacement is likely required.
How To Replace The Reset Switch
Replacement involves removing the old switch and installing a compatible new unit. Confirm the replacement matches the original’s electrical ratings and mounting style. If a wired connector is used, replace the connector or crimp new terminals for a secure fit.
Replacement Steps
Step 1: Power down the furnace and remove the access panel. Step 2: Label and disconnect wires from the old switch. Step 3: Remove mounting screws or clips. Step 4: Install the new switch and reconnect wires, ensuring firm connections. Step 5: Restore power and test furnace operation and switch reset functionality.
Common Installation Issues And Fixes
Poor connections, reversed polarity, incorrect part selection, and mounting stress can cause premature failure. Ensure wires are not pinched, terminals are crimped or soldered correctly, and the switch sits flush. Use dielectric grease on connectors in marine or high-humidity environments to prevent corrosion.
When The Reset Button Won’t Stay Reset
If the reset switch trips again immediately after resetting, it indicates an underlying problem such as motor overload, blocked venting, failed limit thermostat, or damaged wiring. Inspect airflow, clean vents and flue, and check the blower motor amp draw. Persistent trips require deeper diagnostics or professional service.
Related Furnace Components To Inspect
Alongside the reset switch, check the blower motor, limit thermostat, high-temperature cutoff sensor, control board, wiring harness, and vents. Obstructed combustion or exhaust paths and a failing blower motor are frequent root causes of repeated reset trips.
Maintenance Tips To Prevent Reset Trips
Regular maintenance reduces reset switch failures. Clean the furnace compartment and vents, replace air filters, inspect and tighten wiring annually, and lubricate moving parts per the manufacturer’s recommendations. Schedule a yearly professional service for combustion and safety checks.
OEM Vs. Aftermarket Reset Switches
OEM switches match original specifications and mounting points. Aftermarket options can save cost but may differ in durability or fit. If using an aftermarket part, confirm voltage rating, amperage capacity, and physical compatibility with the Atwood furnace model before installation.
Cost And Where To Buy Replacement Parts
Reset switches are generally affordable, ranging from under $10 for simple push-button switches to $20–$40 for OEM assemblies. Purchase from authorized RV parts dealers, manufacturer distributors, or reputable online retailers. Save the furnace model and part number to ensure correct ordering.
Troubleshooting Flowchart (Text)
1. Furnace does not power on: Check fuses, battery, and power at the furnace. 2. Reset switch tripped: Attempt reset after cooling and check continuity. 3. Immediate retrip: Inspect vents, blower motor, and limit sensor. 4. No continuity when reset: Replace switch. 5. Furnace still fails after switch replacement: Test control board and wiring harness.
When To Call A Professional
Call an RV technician when the cause is unclear, when combustion components need inspection, or when electrical diagnostics require specialized tools. Professionals are recommended for gas line repairs, control board replacements, and safety testing to comply with manufacturer and warranty requirements.
Frequently Asked Questions
How Often Should The Reset Switch Be Replaced?
There is no fixed interval; replacement is based on failure or visible wear. With proper maintenance, switches can last many years. Replace immediately if it shows signs of overheating, corrosion, or inconsistent operation.
Can A Reset Switch Be Bypassed?
Bypassing a reset switch is unsafe and voids warranties. Never bypass safety devices; doing so risks fire, carbon monoxide exposure, and severe damage. Replace a faulty switch with a proper part instead.
Does The Reset Switch Protect Against Carbon Monoxide?
The reset switch protects against electrical and thermal faults but does not detect carbon monoxide. Install dedicated carbon monoxide detectors in sleeping areas and follow ventilation guidelines for safe operation.
Documentation And Resources
Useful resources include the furnace owner’s manual, OEM parts lists, wiring diagrams, and RV maintenance guides. Manufacturer technical support and RV forums can provide model-specific advice, but verify solutions against official documentation to avoid incorrect repairs.
Key Takeaways
Locate the reset switch on the blower housing, verify compatibility before replacing, and test with a multimeter for continuity. Regular maintenance and correct part selection reduce repeat trips. If the reset button continues to trip, investigate airflow, blower motor function, and control circuitry or seek professional service.