Muffling the furnace - Outside noise

[Old-Biscuit]

You have a standard 34Kbtu propane furnace....probably Atwood/Dometic

There are NO air/fuel adjustments.....other than LP System Pressure
S/B 11"WC (0.4 psi)
Higher LP System Pressure can result in LOUDER then Normal Flame


***ANY Modifications to Intake/Exhaust Tube WILL result in poor furnace operation
Adding a deflector shield is NOT the cure

Check LP System Pressure...adjust if needed
Check motor operation if source of noise is from motor/air-combustion wheels

RV Propane furnaces are by design a bit nosey as are RV Water Heaters