Improving a Suburban Furnace

Cleaning fan blades may help. Both combustion and circulatory.

Add additional ducting for more airflow. Fan does not work as hard, should draw less power per BTU moved, and the RV will heat faster to give less run time.

Sometimes oil can help. Depends what kind of noise were talking about. Things that dont move get gummy.

Simple answer is you can't.

You can't put a slower fan or fan motor (which would be quieter) in there.

You can't slow down the motor as the furnace WILL over heat and not to mention the same motor serves a dual purpose. One side of the fan blower is for the inside and the other side of the fan blower is the draft inducer for the burner.

Alter either and now you have a non safe or non functional furnace.

Additionally the furnace has a safety switch called the sail switch which will prevent the burner from firing if there is not enough air movement, don't bypass that..

2oldman, that is a pretty dangerous path to go down and I highly doubt you are going to be able to pull this off safely or reliably and not to mention it would take a considerable drop in RPM to reduce the fan noise.. Any drop in RPM will affect not just your inside fan but the draft inducer fan for the burner since both fans SHARE the same motor.. If I were you, I would PM the resident RV furnace guru Dougrainer BEFORE attempting. I suspect he will pretty much say the same thing I have though. Not to mention it will be one whopper of a resistor as far as wattage goes..

My living room furnace is nice and quiet, but the bathroom one is a jet engine. Recently had the motor replaced so I'm not sure what happened there.

Haven't gotten to it yet, but my DIY is going to be a large resistor to try and slow down the fan speed. No, I'm not going to slow it down so much it'll overheat the furnace.