If your Atwood RV furnace isn’t turning on, keeps shutting off, or blows cold air, don’t panic-you’re not alone. RV owners frequently face heating issues with their Atwood Hydro Flame or Atwood Dometic furnaces, especially during cold-weather camping.
The good news? Most issues are easy to resolve as soon as you know where to look.
This Atwood furnace troubleshooting guide will walk you through the most common issues, their causes, and step-by-step solutions.
How an Atwood RV Furnace Works
Understanding how your furnace works helps you identify the problem sooner.
Here’s how your Atwood propane furnace works:
- The thermostat calls for heat.
- The blower motor starts to clear the combustion chamber.
- The sail switch confirms airflow.
- The igniter sparks and the gas valve opens.
- The flame sensor, when ignition is achieved, confirms a sustained flame.
- Warm air circulates through your RV.
If one process in this chain doesn’t work, then your furnace will either lock out or blow cold air.
1. Atwood Furnace Not Turning On
When your Atwood furnace won’t start, start checking the following:
a) Check Power Supply
- Make sure your 12-volt battery is charged. Atwood furnaces require DC power to operate both the fan and control board.
- Check your RV’s electrical panel for blown fuses or tripped circuit breakers.
b) Check Thermostat Operation
- Set the thermostat to “HEAT.”
- Increase the temperature over ambient.
- If the fan doesn’t start, check thermostat wiring or try a known-good replacement.
c) Check furnace switch and connections
Most models by Atwood have an on/off switch or inline fuse somewhere around the furnace. Ensure that it is ON, and the fuse is intact.
If nothing happens still, it may be due to a faulty control board or a loose ground connection.
Also read: Bryant Furnace Troubleshooting
2. Atwood Furnace Blows Cold Air
When the blower runs but air never warms up, the process of ignition doesn’t complete.
a) Low Battery Voltage
If the voltage falls below 10.5 V the blower may still rotate, but not fast enough to trip the sail switch to allow ignition.
Charge your RV battery completely, or hook up to shore power.
b) Sail Switch Not Closing
The sail switch detects air flow. If it’s sticky or dusty, the furnace won’t light.
Fix: The switch should be removed and cleaned with compressed air or contact cleaner.
c) Problem with igniter or flame sensor
Check the igniter for cracks, and the flame sensor for corrosion. Replace if damaged.
d) Gas Supply Problem
Be sure that the propane tank is open and not empty. Check hoses for kinks or leaks.
3. Atwood Furnace Turns On Then Shuts Off
This is one of the most common Atwood furnace problems. The furnace lights up but briefly then goes out:
Possible Causes:
- Dirty flame sensor
- Blocked exhaust or intake vent
- Weak igniter
- Faulty circuit board
Correct Steps:
- Switch off all power and gas.
- Remove the flame sensor (small metal rod near the burner).
- Clean with fine steel wool or emery cloth.
- Check all intake and exhaust vents outside your RV for insect nests or debris.
- Restart the furnace.
In such cases, the control board may be misreading the flame signal and needs to be replaced.
4. Atwood Furnace Fan Runs But No Heat
If you hear the fan and the heat doesn’t come out, it’s probably an issue with gas or ignition.
a) Check the Propane Regulator
Your RV’s propane regulator controls gas pressure. Low pressure prevents ignition.
Test with the stove on: if the flame is weak or yellow, replace the regulator.
b) Dirty Burner Assembly
Soot, rust, or debris in the burner itself can impede proper gas flow.
Clean the burner tube carefully with compressed air by taking it out:
c) Faulty Gas Valve
The valve may not open when commanded if all other parts check out.
Check for voltage at the valve with a multimeter when the furnace attempts to fire.
Also read: Trane Thermostat Troubleshooting
5. Atwood Furnace Keeps Blowing Fuse
If your furnace keeps blowing the 15A fuse, there’s probably an electrical short.
Common Causes:
- Damaged wiring insulation
- Shorted blower motor
- Faulty control board
Fix:
- Check all visible wiring for rub-through or melted spots.
- Disconnect the blower motor and see if the fuse holds. If it does, replace the motor.
6. Atwood Furnace Won’t Light (Clicks But No Flame)
Clicking means the igniter is sparking, but gas isn’t lighting.
Possible Causes & Fixes:
- Air in the gas line – Bleed the line by running the stove burners for a few minutes.
- Dirty igniter electrode – Clean it carefully using sandpaper.
- Faulty gas valve coil – replace if not opening.
- Blocked burner orifice – clean with compressed air to remove carbon buildup.
7. Atwood Furnace Blower Won’t Stop Running
If the blower runs continually even after the flame has gone out:
a) Stuck relay on the control board
The fan relay on the board might have failed closed. Replace the board.
b) High-Limit Switch Open
When the furnace overheats, the limit switch stays open until it cools.
Check for blocked ducts or dirty filters hindering airflow.
8. Atwood Furnace Smells or Produces Soot
Unusual odors or soot suggest combustion problems.
- Burning Dust: Normal the first time you use the furnace in a season.
- Propane Odor: Turn off gas at once — leak suspected.
- Black Soot: Incomplete combustion. Clean burner and check air intake.
9. Atwood Furnace Error Codes (LED Blinking Light)
Most Atwood furnaces have an LED diagnostic light on the control board.
Here’s what common blink codes mean:
| Blink Pattern | Meaning | Possible Fix |
| 1 Blink | Ignition failure | Check igniter or flame sensor |
| 2 Blinks | Airflow issue | Clean sail switch or blower |
| 3 Blinks | Limit switch open | Check for overheating or blocked vents |
| 4 Blinks | Low 12V power | Recharge or replace RV battery |
| 5 Blinks | Circuit board failure | Replace control board |
Always note the blink pattern before resetting your furnace.
10. How to Reset an Atwood Furnace
Resetting clears temporary lockouts.
Steps:
- Switch off the furnace switch or breaker.
- Wait 30 seconds.
- Flip the toggle back on.
- If your model has a manual reset on the blower motor, press it once.
If the furnace still won’t operate, check for stored fault codes.
Also read: Gree Mini Split Troubleshooting.
Preventive Maintenance Tips
Routine maintenance prevents most Atwood furnace troubleshooting headaches:
- Clean the burner and flame sensor annually.
- Replace air return filters regularly.
- Ensure that vents are free from obstructive materials.
- Check propane hoses and fittings for leaks.
- Lubricate blower motor bearings, if applicable.
- Have the system inspected before each camping season.
When to Call a Professional
Many issues can be fixed with DIY repairs, but for issues described here or any others that you’re not comfortable with, contact an RV service technician:
- Either the gas valve or control board requires replacing.
- You smell persistent propane.
- After all checks, the furnace cycles erratically.
- Electrical components test incorrectly.
A professional can safely check gas pressure, verify voltage readings, and recalibrate the control board.
Frequently Asked Questions (FAQ)
1. Why does my Atwood furnace keep shutting off after a few seconds?
It’s probably because the flame sensor isn’t detecting a stable flame. Clean the sensor and verify for low voltage or gas flow issues.
2. My Atwood furnace blower runs, but no heat — what’s wrong?
A faulty sail switch, dirty igniter, or empty propane tank may be preventing ignition even though the fan is operating.
3. What is the correct voltage for an Atwood RV furnace?
The correct range is between 10.5V and 13.5V DC. Anything lower than 10.5V can lead to ignition failure.
4. How long should an Atwood furnace last?
With proper care and maintenance, an Atwood furnace can last 10–15 years of reliable service.
5. Is it safe to run the Atwood furnace while driving?
Not recommended. For safety reasons and to prevent wind pressure damage to the exhaust system, turn off the furnace during travel.
Final Thoughts
Your Atwood furnace is built for durability, but dust, voltage drops, and airflow restrictions can lead to performance issues over time.
Most problems — such as a dirty flame sensor, weak battery, or blocked vent — can often be resolved quickly with basic tools and a little patience.
By following this Atwood furnace troubleshooting guide, you’ll keep your RV warm and your furnace running efficiently all season long.
If the furnace still doesn’t work after all these steps, consult a certified RV technician to safely check gas pressure and control circuits.
🔑 Key Takeaway
Most common Atwood furnace failures can be traced back to low voltage, dirty components, or blocked airflow.
Keep your system clean, your battery charged, and your propane flowing — and you’ll avoid 90% of heating issues.
