Atwood 8525 Furnace Propane Smell: Safety Issues, Causes & Step-by-Step Fix

Tools & Parts Needed

Find these on Amazon: Digital Manometer , Combustible Gas Detector , High Temperature RTV Sealant , Inspection Mirror Set

The Quick Fix

A propane smell from your Atwood 8525 furnace during operation is a serious safety issue that typically indicates incomplete combustion, improper burner installation, or a damaged heat exchanger.

Gather These First

• Flashlight or headlamp
• Mirror (small inspection mirror preferred)
• Screwdriver set
• Multimeter
• Manometer (for gas pressure testing)
• Combustible gas detector
• New gaskets/seals if needed
• High-temperature RTV sealant

Your Action Plan

1. Turn off the furnace, shut off propane supply at the tank, and allow the furnace to cool completely before beginning any inspection work. Ensure adequate ventilation in the work area during all testing procedures.
2. Remove the furnace access panel and visually inspect the burner assembly installation. Look for gaps, misalignment, or missing gaskets around the burner mounting area.
3. Check the burner gasket where the burner assembly meets the combustion chamber. This gasket must create a complete seal to prevent combustion gases from escaping.
4. Inspect the burner orifice to ensure it matches the BTU rating specified for your Atwood 8525 (typically 12,000 BTU). The orifice should be clean and properly sized.
5. Examine the air intake connections around the burner assembly. Any unsealed openings can disrupt the air-to-gas mixture and cause incomplete combustion.
6. Check the heat exchanger for cracks or damage using a flashlight and mirror. Look particularly around welded seams and the combustion chamber area.
7. Test gas pressure at the furnace using a manometer to ensure proper pressure (typically 11 inches water column for propane).
8. After completing all repairs and ensuring no gas leaks, have a certified RV technician verify proper burner flame pattern and operation before use. When professionally tested, the flame should be blue with minimal yellow tips.

Understanding the Issue

Since you recently replaced the burner assembly, the most likely causes are incorrect burner positioning, improper air intake sealing, or a damaged burner gasket.

Safety Warning: Stop using the furnace immediately until the issue is resolved. Propane smell inside your RV can indicate dangerous carbon monoxide production or gas leaks.

1. Improper Burner Installation

Since you recently replaced the burner assembly, this is the most probable cause. The burner must be perfectly aligned with the combustion chamber and properly sealed.

2. Damaged or Missing Gaskets

The gasket between the burner assembly and combustion chamber may be damaged, missing, or improperly seated, allowing combustion gases to escape into the RV.

3. Incorrect Air-to-Gas Mixture

If the burner orifice size is wrong or air intake is blocked/unsealed, incomplete combustion occurs, creating the propane smell.

4. Heat Exchanger Damage

A cracked or damaged heat exchanger can allow combustion gases to mix with the circulating air inside your RV.

Burner Realignment

Remove and reinstall the burner assembly, ensuring proper alignment with the combustion chamber. The burner must sit flush and square with no gaps.

Gasket Replacement

Replace the burner gasket with a new high-temperature gasket designed for your Atwood 8525. Apply a thin bead of high-temperature RTV sealant if specified.

Air Intake Sealing

Ensure all air intake connections are properly sealed and that the combustion air intake is drawing outside air, not interior air.

Beyond DIY Territory

Contact a certified RV technician immediately if:

• You find cracks in the heat exchanger
• Gas pressure readings are incorrect
• You're uncomfortable working with propane appliances
• The propane smell persists after your repairs
• You detect any signs of carbon monoxide (headaches, dizziness, nausea)

Heat exchanger replacement and complex combustion issues require professional expertise and specialized tools.

Preventive Measures

• Always use genuine Atwood replacement parts and gaskets
• Have your furnace professionally inspected annually
• Keep combustion air intakes clear of debris
• Never operate the furnace if you smell propane inside
• Install propane and carbon monoxide detectors in your RV
• Document your repairs with photos for future reference