RV Repair: Suburban Furnace maintenance, furnace maintenance, suburban furnace

Question
I would like to access the blower cage and sail switch of my trailer furnace to clean them and to just generally look around and determine the condition of any gaskets I encounter. The model number is SF-25F (Suburban) and it's 10 years old. It is my understanding that that particular series is only serviceable from the interior of the trailer. If I'm wrong about that, let me know. I do not intend on attempting any repair, only cleaning and inspection. Other then an occasional failure to ignite, the furnace works properly. No soot at the exhaust tube.

Are you familar enough with that model furnace to step me through what is neccesary for me to access the sail switch and blower cage? I'm mechanically inclined, follow directions well, handy with tools, and have a complete understanding of how the furnace works. Once I'm inside I'll know what I'm looking at. I just want to make sure I don't break something getting in there. My apprehension is with issues like: Does the vent cap assembly on the outside of the trailer need removed? Once I disconnect the gas connection, can I just slide the guts out? Those type of things.

Thank you in advance for any help you can render,

Ryan K. Watson

Answer
Ryan,

    You shouldn't have any problem working on this furnace unless the way and place it's mounted prohibit it from sliding straight out.  You will first want to remove the vent on the exterior of the unit and turn off your gas supply.  Then disconnect the power wires at the furnace.  Next you will need to remove the gas line.  On some suburban furnaces you also will need to remove the gas fitting that goes through the cabinet, on others the cabinet is slotted, and I don't remember which way this particular cabinet is set up.  Now you need to remove the two screws that hold the cabinet front on and remove it.  You should see a single screw in the middle of the unit down low.  Once you remove this you should be able to slide the furnace out of the cabinet.  After you have done this you should be able to see all the components you mentioned and be able to clean and inspect them.  If you decide to clean the burn chamber, they recommend removing the burner assembly and the blower assembly from it first.  When you are done just slide the unit back into the cabinet, reinstall the mounting screw, reinstall the cabinet front, reinstall the gas line and fitting if necessary, turn the gas back on and check your fittings for leaks with a soap and water solution (Mr. Bubbles is a good one,  if you don't have any just make sure your soap doesn't contain any ammonia because it will deteriorate the brass fittings), reconnect your power wires, and finally reinstall your vent assembly on the outside.  I hope this helps and good luck.

Darren