FURNACE REMOVAL

Discussion in 'General RVing' started by ARCHER, Apr 29, 2006.

  1. ARCHER

    ARCHER Senior Member

    Getting ready to remove my Surburban furnace in order to do some maintenance and repairs. Never removed one before, so looking for suggestions/hints/tips on doing this. I know I need to remove the LP fitting (LP turned off, of course) and two screws on base of furnace towards the open panel door (89 Winn, Chieftain) where I can access the furnace. Is there other mounting screws in the rear that are either hard to get too or screws holding the furnace onto the duct work or ??? :) :dead: ;)
     
  2. Grandview Trailer Sa

    Grandview Trailer Sa Senior Member

    FURNACE REMOVAL

    Hey Archer,
    Usually the furnace is only held in by the screws you talk about. You might find some in the rear, but not always remove the back panel and see. If you have 4" round duct work rotate the fitting in the furnace and it will unlock. You don't have to take the clamp and tubing loose. Be sure to label the wires so you get them back correct if you cannot unplug them from the board.
    Good luck, but since you asked a few days ago, you may have already done this.
     
  3. Kirk

    Kirk Senior Member

    FURNACE REMOVAL

    On the one I had in my 87 Allegro, there were screws that came from the outside of the plate that covered the exhaust port. I believe that there were four of them and they had to be removed in order to remove the furnace.
     
  4. ARCHER

    ARCHER Senior Member

    FURNACE REMOVAL

    Grandview, tks.
    Kirk, I have the same four screws that hold the outside exhaust port in place and have to take it off in order to access the furnace. I have a outside cover with hinge to access the main part of the furnace for removal. Just need to take the LP line loose from supply line and from furnace, then the two screws in front. I hope Grandview is correct in that there may not be screws in rear, as it is a tight area to get too. Hopefully, I won't have any problem getting to the ductwork in rear. Will be trying to remove the entire furnace so that I can clean, and find out why it won't light (clicks, but won't light). I think it might be either blockage (dirt,etc.), board, limit switch, or flywheel (can't remember the name of this switch, but operaters when blower blows) switch. Furnace has never been out of the RV, so is probably dirty and possibly rusted up some. It worked fine in Dec, then sat for two months and then would not light/fire up. I'll let ya know what I find out after I get it out, cleaned and fixed. Tks again for the suggestions/guidance. ;)
     
  5. Kirk

    Kirk Senior Member

    FURNACE REMOVAL

    I guess that I have not stayed current on Suburban furnaces since I changed to an Atwood. I was just looking through a couple of manuals and see that they have made some good changes! In any case, you might be wise to visit http://bryantrv.com/docs.html and down-load the service information on your furnace. I think that you would find it to be pretty helpful.

    I think that the "sail switch" is probably what you are thinking of. It's failure to close when the blower starts is the most common reason for the problem that you have. Of course, there can be several different reasons that might cause that. By far the most common is dirt or some other obstruction in the air flow path. That same motor turns two blowers, one to move combustion air and the other moves the inside air through the heat exchanger. The sail switch is a safety device to prevent the gas flow when there is not enough air movement through the furnace. There is a good chance that if you bench test it you can check and determine if the sail switch is closing or not, without connecting the propane to allow it to burn. Very often a complete cleaning of all parts of the furnace will make that problem go away. Just use jumpers to supply the blower motor with 12V power and put your meter across the sail switch to see if it closes.

    I would assume that you realize that if your furnace gets any less than 11V it may not close the sail switch and at 10.5V it won't close. The reason I ask is to be sure that you have checked the power to the furnace before you remove it.
     
  6. ARCHER

    ARCHER Senior Member

    FURNACE REMOVAL

    tks Kirk. The blower comes on just fine so I assumed the power was ok going to the furnace. It clicks and trys to start. I'll check the power to it before removing it (if I can get to the wires to check it).
     
  7. ARCHER

    ARCHER Senior Member

    FURNACE REMOVAL

    Kirk, oops. Just thought of something else to tell you. I manually operated the sail switch (with furnace in off position on thermostat and got LP smell so guessed the sail switch was ok when power applied and blower was on. Correct assumption?
     
  8. ARCHER

    ARCHER Senior Member

    FURNACE REMOVAL

    Kirk, Checked out the web site (Bryantrv). Thanks so much. Great and I printed the part for my furnace and can use it as a "total" guide to walk me through maintenance and repairs for the ole furnace. I'll let ya know what I find when I get into it. tks again
     

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