Furnace-No Power...Now What?

Discussion in 'Heating / Cooling Systems' started by JETent, Jan 31, 2012.

  1. JETent

    JETent JT

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    Dear Portal Pals-

    I have 2008 Fleetwood with the Atwood 7916-II furnace. I recently tried to use the furnace for the first time (less than a year ownership). The furnace unit does not seem to be getting any power when hooked to shore or battery.

    I have followed directions step by step for firing up the furnace with no results. Checked fuses and circuit breakers and all are good. The LED indicator on the furnace control panel does not light up at all. When set to ON, the thermostat settings have no impact/control of the furnace--might as well be OFF. The off/reset rocker switch on the furnace has been properly set to reset when trying to light the furnace. There is no life to the furnace. Successfully completed the fridge mod this summer and do not believe the fridge mod directly impacted the furnace wiring. The fridge mod works great. All other 12v devices (pump, lights, radio, etc.) are working great.

    I suspect the thermostat is bad/not functioning. The atwood thermostat is a crude little device that appears to be very simple. Hard to believe it could fail. All visible wiring looks good and is connected tightly. I have read about the "sail switch" but do not believe it has influence on power--at least to a degree that would prevent the trouble shooting LED from lighting up.

    Hitting a wall with my current pop up know how. Any ideas out there to help root cause the problem? Really don't want to haul the PU down to the dealer. Really.

    Any ideas/sharing of experience would be helpful.

    FURNACE
    [​IMG]
    CONTROL BOARD-DEAD
    [​IMG]
    THERMOSTAT-BROKEN?
    [​IMG]


    As always, thanks.
    JT
     
  2. rabird

    rabird Howdy!

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    I'd check for power with a volt meter.

    See page 8 for wiring (I believe your's is the first pic).
    See page 30 for troubleshooting.
    http://bryantrv.com/docs2/docs/hflamefurn04.pdf

    There should be a three wire plug outside the furnace that supplies power.
    This old Bayside wiring diagram may help (click then enlarge)
    [​IMG]
     
  3. Raycfe

    Raycfe Waterford Ct.

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    Going to ask a couple of silly questions ......... do the dome lights work? If not check the galley safety switch. Our safety switch shuts off the furnace. And the thermostat has a hard to move on/off switch on the top as well as the on/off on the furnace.
     
  4. Harvardroger

    Harvardroger If it feels good, do it! If it hurts, Stop!

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    Double check the little switch on the top of the thermostat. (I hauled my Niagara back to the dealer with the same symptoms and found I had not have it in the right possition) [:D]
     
  5. JETent

    JETent JT

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    Harvardroger-

    From what I can tell, there are only two positions for the thermostat nubbin. Fingerbuster to get the the nub to go into on or off. I have pushed this from on/off so many times, can't see how there is a setting I am missing. I did not want to break the plastic nub by exerting too much force and believe I have exhausted the thermostat on/off "not in the correct position" possibility. Thanks for the suggestion and I will try again this weekend. If I bust the plastic nub, so what.


    Later,
    JT
     
  6. JETent

    JETent JT

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    Raycfe-

    Thanks for the reply. Yes, all of the 12v items are good from shore and battery. The galley switch works like a charm. Thermo on/off is on the ON position. I have pushed the thermo on/off really hard with my fingers and pliers and screwdrivers and have determined there are no other possible (mechanical) settings for that thermo on/off switch. The 7916-II Atwood Furnace does not have an ON/OFF switch on the unit itself, only an OFF/RESET rocker style switch. I have used this switch as directed in the users guide, with no luck.

    Thanks,
    JT
     
  7. JETent

    JETent JT

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    Bupkis-

    Thanks for the suggestions. I have (given as a gift) a voltmeter and am trying to figure out how to use it. From my fridge mod experience, I am too thick to understand the voltmeter and perhaps the voltmeter is too fancy for my skillset. A persona problem I will continue to address.

    On the '08 Fleetwood E3, the furnace has no exterior presence other than the venting duct. The three wire plug you mention may be accessible/viewable by extracting the furnace unit out of the cabinet from inside the PU. Lack of electricity would lend to the belief that the three pronger has become disconnected. Pulling the furnace out of the unit to check the three prong will be an all day event for me, but a this point seems unavoidable. Thanks for pointing out that there is a three pronger for the furnace.

    What about the "SAIL SWITCH"? Do you know about these and if so, in a failure situation, will they prevent electricity from getting to the furnace? If I am going to have to remove the entire furnace to double check if the three pronger is connected, that would probably afford me the opportunity to check the SAIL SWITCH, if I correctly understand where it is located.

    I will check the wiring diagrams for checkpoints. Having trouble reading the details from the JPEG.


    Thanks for your help. It is truly appreciate.



    Later,
    JT
     
  8. JETent

    JETent JT

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    Bupkis-

    Found the wiring PDF from the link you provided. Thanks. I think once I figure out how to use the voltmeter, I can check to see if power is coming into the thermostat via the red (aka orange on my rig) from the (non-tripped) circuit breaker. Thanks again for the info. Any other advice is certainly welcome. Will keep this thread updated.


    Later,
    JT
     
  9. rabird

    rabird Howdy!

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    The sail switch doesn't come into play until the fan motor is running. The fan must turn fast enough for the switch to close. When it closes (and enough time has passed), the circuit board then sends power to the gas valve to open and to the igniter.

    One thing I've heard of to eliminate the thermostat is to disconnect it then connect the 2 wires together eliminating the thermostat (always on), the fan motor should start right away.

    Look on the circuit board for the power coming from the reset/off switch, I think it is the red wire with the pink plastic cover. Disconnect the power wire and probe for voltage between the power wire and ground (black wire or chassis). I believe it should have power anytime the breaker is not off. The BLO wire is controlled by the circuit board/thermostat.
     
  10. marcham

    marcham New Member

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    Have you found the wiring connectors between the furnace and the trailer's main wiring bundle? May have become undone on a rough road ...
     
  11. papachaz

    papachaz New Member

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    you really have to completely remove the furnace just to see if it's plugged in? wow, no way to pull the vent cover outside to check it? that's crazy.....i would think it would be like the frig and you could access the plug by pulling the outside vent off...
     
  12. Raycfe

    Raycfe Waterford Ct.

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    As for using the voltmeter .......... this maybe way basic, but .......... set the voltmeter scale to 20 VDC ........... take a flashlight or any other battery and put the black lead on the negative and the red on the positive .......... should read battery voltage. To use in the PUP ...... connect the black lead to the metal PUP frame or any white wire going to the frame and use the red lead to probe for power/voltage ............... don't worry 12 volts can not "bite" you. To check a 110 VAC outlet .... change the scale to 200 VAC and probe the outlet terminals carefully as this can bite you. Something else you should try is ..... take a piece of wire ....... set the scale to "Q" or resistance ........ put both the black and red leads together ........ should read 1.0000 no resistance ..... remove a lead ........ should read 0 alot of resistance/no connection ....... now do the wire ..... one lead at one end and the other at the other end ....... reads 1 wire is good ...... reads 0 wire is broken/open ........... you can do this this just about anything metal, switches, bulbs, etc. Have fun.
     
  13. marcham

    marcham New Member

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    Plug can be accessed from the inside, just lift the grill ...
     
  14. JETent

    JETent JT

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    All-

    Update to the furnace saga.

    Talked to an RV maintenance guy at the Austin(Tx) RV Expo a couple of weeks ago. I explained the furnace issue to him and thought it was the thermostat. I asked him the best way to bypass the thermostat. He told me to take a pocket knife and nick each of the two wires behind the thermostat then use the blade to bypass the thermostat. I finally got a chance to try it out today and guess what? The blower fired right up. Good enough for me. I will be ordering a new (not Atwood) thermostat.

    Thanks again for everyone sharing their experience and knowledge most truly appreciate your willingness to do so.

    Isn't that great? I will have the furnace fixed just in time for summer. Beauty.


    Later,
    JT
     
  15. Bonniy

    Bonniy arizona bred and born

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    we have this problem too, the atwood is horrable, our dealer said that the atwood craps out all the time and we need to get a new thermastat, but am not sure what kind to get or how to install it, oh well, so we have an litte mr buddy one to use on cold days, wish I knew what kind to buy and how to install the darn thermastat thingy
     
  16. JETent

    JETent JT

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    Bonniy-

    I ordered a White Rodgers 1C20-101 "Heat Only" Thermostat (my A/C is not controlled via that thermostat). This is a model suggested by the same service guy I spoke with at the RV Expo. He suggested it for two reasons: 1.) Atwood thermos are known to be problematic and 2.) this was the only other one his dealership carried (that would work in my PUP). I ordered the replacement thermo from Amazon. In exchanging info with other folks on the portal, some people go to Lowes or home depot to buy replacement thermostats. I played it safe with my selection. Cost was about $25.00 w/shipping.

    Here are my Famous Last Words. My approach to the thermostat install is that there are only two wires going into the thing, how hard can it be? I will let you know how it goes.

    We have been using a ceramic electric heater (or no heater when dry camping) to get by while the thermostat is out. I almost went the way of Mr. Buddy, but then didn't.

    Good luck and stay tuned to what will hopefully be my last update.


    Later,
    JT
     
  17. JETent

    JETent JT

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    Portal-

    Another chapter closed. Finally.

    Finished replacing the broken Atwood thermostat with an equally simple White Rodgers thermostat. Simple process mostly. Hardest part was self inflicted as I attempted to use pop rivets to mount the new thermostat to the plastic mounting housing(?). Anyway. I ended up using machine screws and nuts to secure it to the mounting housing. I applied relatively hefty amounts of Loctite Threadlocker to the screws/nuts to help prevent them from wiggling loose.

    The furnace fired right up, gas kicked in and in less than 2m I had some very hot hair blasting out of the unit! I have been wrestling with this diagnosis/repair since I/we discovered (the hard way) the furnace was inoperable during our (very cold) coastal New Years eve adventure. So, this one is done. End result is a slightly crooked thermostat and a new ceramic whirlpool space heater as a backup plan (which works great, btw).


    [CAM] Here a couple of pics for your viewing pleasure:

    Slightly crooked, but very functional:
    [​IMG]

    Machine screw mounted rather than pop rivets (rivets I have were not long enough for the new therm mounting holes):
    [​IMG]

    Whirlpool ceramic space heater--an adequate unit:
    [​IMG]


    Thanks again to everyone for helping me with this one. Learned some cool stuff along the way. Just in time for summer! Now....on to replacing the water heater gas control valve, then adjust, clean and lube the whiffle tree and cables. And make one of those "three tiered" wooden levelers. So much to do and made much more enjoyable by the portal.

    See yall out there....



    Later,
    JT
     
  18. desertlady

    desertlady Member

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    Where is the "galley safety switch?" I just experienced no dome lights and no furnace on my last camping trip. Camped 2 nights Lake Roper with no problems, drove to Lake Patagonia and then no dome lights or furnace. Check all fuses, no problems. AC worked, and things like plug in appliances worked. Thoughts? Suggestions? [?:~{]
     
  19. Hacksaw

    Hacksaw Active Member

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    The Galley switch is in between the upper and lower section of your galley (sink/stove).It's a little rocker switch that will only allow the 12v to work if it is closed (meaning the galley is in the up position) They sometimes go bad,they sometimes get disconnected and sometimes they need to be adjusted to make contact. Another place to look for no power to the dome lights is the connector where the wire comes up from the body and into the tenting...that one had me crazy for about 30 minutes one day...
     
  20. BajaPup

    BajaPup New Member

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    JETent, glad you figured it out, and thanks for following through on the process. After fiddling with an Atwood thermostat, I'll probably buy something better, too.

    I tracked down my dead furnace fault to a disconnected plug to the thermostat. Someone had to have unplugged it, but I don't know why. I also noticed a layer of soot had built up on the thermostat's contacts. If a furnace will fire when the thermostat is bypassed, cleaning the contacts may be the solution. Assuming the tiny nub-switch is ON, of course. :)
     

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