Hydro flame FA7916-II blows cold air only

Discussion in 'Heating / Cooling Systems' started by EdZilla, Sep 19, 2017.

  1. EdZilla

    EdZilla Member

    Messages:
    76
    Likes Received:
    10
    Joined:
    Sep 19, 2017
    Location:
    Denver
    My 1994 Starcraft Starflyer pop up has a hydro flame FA7916-II furnace. I can get the fan going and I can light the pilot, but it does not blow hot air.

    The instructions say that it does not have a pilot, rather, it has an "ignition device". Actually, there is a pilot light so this is a point of confusion.

    The first 7 steps are about shutting everything off and waiting for gas to clear.
    Step 8 says :
    "Turn on power switch provided from valve. "

    "Provided from valve"? What does that mean?

    There is an on off switch on the front and a switch by a gas valve in the exterior panel. The Valve and the 12v switch interfere with each other in that if you open the valve it blocks the switch so you can't turn on the switch all the way.

    The instructions say to replace the panel and turn on power to appliance.

    Apparently it is then supposed to ignite by itself but that does not happen. The fan comes on but it never gets hot.
     
    Last edited: Sep 19, 2017
  2. theseus

    theseus Centerville, OH

    Messages:
    2,860
    Likes Received:
    410
    Joined:
    Feb 6, 2007
    Location:
    Centerville, OH
    The 7900 series from hydroflame is DSI or direct spark ignition. If you have a pilot light, it's not the model you have reported. Is that the model number that is on the inside of the furnace?
     
  3. Customer

    Customer Well-Known Member

    Messages:
    2,436
    Likes Received:
    243
    Joined:
    Jun 5, 2014
    There should be no exterior controls on a furnace, maybe you are looking at the refrigerator controls.
     
    EdZilla likes this.
  4. EdZilla

    EdZilla Member

    Messages:
    76
    Likes Received:
    10
    Joined:
    Sep 19, 2017
    Location:
    Denver
  5. EdZilla

    EdZilla Member

    Messages:
    76
    Likes Received:
    10
    Joined:
    Sep 19, 2017
    Location:
    Denver
    That's likely the case. See the photo of the exterior panel I posted elsewhere.

    There must be some external control, in order to turn on the gas for example?

    Also, the front of the furnace has a small on/off switch which appears to do nothing. The only way to get the fan to turn on is to set the thermostat all the way to the right, which is counter to the furnace instructions.
     
  6. rabird

    rabird Howdy!

    Messages:
    6,693
    Likes Received:
    298
    Joined:
    Mar 3, 2006
    Location:
    TX
    picd of these on/off switches
    if the front grill is removed there is generally a small on/off switch that can turn power on/off to the gas valve.
    It needs to be on for the gas valve to open when the fan speed is high enough to close the sail switch.
     
    EdZilla likes this.
  7. tfischer

    tfischer Well-Known Member

    Messages:
    3,511
    Likes Received:
    1,021
    Joined:
    May 21, 2014
    Location:
    Plymouth (Minneapolis) Minnesota
    That second picture is indeed your refrigerator, and is unrelated to the heater. Note the phrase "This refrigeration unit..." on the black device.
     
    Spridle likes this.
  8. EdZilla

    EdZilla Member

    Messages:
    76
    Likes Received:
    10
    Joined:
    Sep 19, 2017
    Location:
    Denver
    Ok, the refrigerator requires a pilot light, and the heater doesn't, eh?
    Although counter intuitive, got it.

    I assumed that to start the furnace, I needed to turn on the gas at the valve where the refrigerator controls are. Is this not the case? Is the pilot light only for the refrigerator?

    If it's not the case that I need to open a valve behind the furnace, then I just need to turn on the gas at the main tank before I start the furnace?

    If So, then to start the furnace, is the is the procedure?
    1. Set the thermostat to high.
    2. Turn on the main 12V circuit.
    3. Turn on the switch on the front of the furnace
    4. Wait for the fan to start.
    2. Turn on the gas at the main tank
    5. Wait for the heat to come out of the furnace.

    Here is a picture of the front of the furnace. Note the tiny on/off rocker switch.

    Please advise.

    Ed
     
  9. jmkay1

    jmkay1 2004 Fleetwood/Coleman Utah

    Messages:
    4,796
    Likes Received:
    1,671
    Joined:
    Oct 10, 2013
    Location:
    Northern Virginia
    The refrigerator controls and furnace are completely separate units. Although I do not have the same furnace I think you may be making it more complicated than it is. On mine as long as I have the gas on from the tank and turn the thermostat on at the set temperature the furnace turns on. I can hear a light click when it tries to fire up, and will continue to try firing a few times until it stops trying. When I don't get heat especially if it hasn't been used in awhile I assume air in the lines. I turn the furnace off, use the stove for a bit to get the propane flowing and try the furnace again. I have no valve behind my furnace and no outside controls for it. If there is enough propane getting to the furnace it automatically lights and I have heat. Sometimes bugs may have made a nest in the lines which is preventing a good enough gas flow to the furnace. Also check to see if perhaps any critters made a nest in the outside furnace vent.
     
    EdZilla and theseus like this.
  10. chambo

    chambo Active Member

    Messages:
    358
    Likes Received:
    113
    Joined:
    Apr 27, 2015
    Location:
    Southern California
    I would do your steps in this order: 2, 2, 3, 1, 4, 5. You have two step 2's listed, I would do both of those first. Also bleed your propane lines be lighting the stove first.
     
    EdZilla likes this.
  11. chambo

    chambo Active Member

    Messages:
    358
    Likes Received:
    113
    Joined:
    Apr 27, 2015
    Location:
    Southern California
    It also likes like the red wire in your photo might be disconnected. Hard to tell.
     
    EdZilla and Spridle like this.
  12. Spridle

    Spridle Active Member

    Messages:
    846
    Likes Received:
    63
    Joined:
    Jun 6, 2011
    Yea disconnected and almost looks like someone was messing with it. But for sure it's not going to fire without the solenoid kicking in.
     
    EdZilla likes this.
  13. theseus

    theseus Centerville, OH

    Messages:
    2,860
    Likes Received:
    410
    Joined:
    Feb 6, 2007
    Location:
    Centerville, OH
    I agree. It looks disconnected. Also the switch on the front of the unit needs to be in the on position.

    If you have an Atwood thermostat, it also has another on/off switch on the bottom of the thermostat. A Suburban thermostat has the on/off switch as part of the slider.
     
  14. rabird

    rabird Howdy!

    Messages:
    6,693
    Likes Received:
    298
    Joined:
    Mar 3, 2006
    Location:
    TX
    connect the loose red wire to the gas valve prong.

    Turn the switch on the front of the furnace to ON

    Open the propane supply

    turn the thermostat on and adjust so it 'calls' for heat.

    Now listen, the fan should come on and then if it spins fast enough you should hear the igniter click try to start the propane burner. If ya hear a 'gush' it likely fired up, enjoy heat!
     
    EdZilla, neighbormike and theseus like this.
  15. tfischer

    tfischer Well-Known Member

    Messages:
    3,511
    Likes Received:
    1,021
    Joined:
    May 21, 2014
    Location:
    Plymouth (Minneapolis) Minnesota
    Note that it might take awhile to get heat the first time when you connect a propane tank, as it takes time to purge the air out.

    On my unit if it doesn't fire in awhile it will give up and shut down, until you turn the thermostat off and back on again.

    Regarding the fridge... yep totally separate with everything else in the popup. With the access panel and all the official looking controls, you're not the first person to assume that it did more than just run the refrigerator. But you're literally staring at the back of the fridge when your'e inside the access panel. The furnace is totally separate (mine's on the opposite side of the trailer even)
     
    EdZilla likes this.
  16. Douggro

    Douggro Active Member

    Messages:
    317
    Likes Received:
    66
    Joined:
    Jul 26, 2017
    Location:
    Seattle, WA
    No pilot on that model, for sure. Definitely the red wire on the left in your pic is disconnected from that empty lug on the left coil; get that fixed or the unit won't fire. Both those red wires should go back to the ON/OFF switch. The other side of the switch goes to the controller board.
    Should not be a gas valve to the furnace - standard is it's tied to the main gas supply directly. But check anyways in case a PO did some modifications.

    Operation sequence:
    1. Open your LP tank valve. (Purging the LP line by running your galley stove for a minute will help get gas to the furnace.)
    2. Turn power on (battery or shore power - functions on either).
    3. Turn furnace switch to ON.
    4. Make sure thermostat is ON (if so equipped) and set the temperature to engage the furnace.
    It will take 15-20 seconds from the time the thermostat engages for the furnace fan to come on, then the fan will run for another 15-20 seconds before the gas valve opens and the ignitor fires. You should hear the ignitor clicking a few times before the furnace lights up. If it fails to light on the first startup sequence, turn the furnace switch off and wait a few minutes and try again - it may take a cycle or two to get propane to the valve. If it still doesn't light (you'll hear lots of clicking from the ignitor then the blower will shut off after a minute or so) after a few cycles, deeper troubleshooting is required.
     
    EdZilla likes this.
  17. EdZilla

    EdZilla Member

    Messages:
    76
    Likes Received:
    10
    Joined:
    Sep 19, 2017
    Location:
    Denver
    Thanks for all the replies. You guys are great.

    The red wire was definitely not connected. Good catch guys, and I'm a little embarrassed I didn't see it.
    However, that doesn't solve the problem. I still have no heat, and no igniter clicks.

    I've followed the steps above, and I've also made sure that the stove lights to be sure that there's gas in the line.
    When I turn on the main battery power (the fan starts nearly immediately), and then I turn on the furnace switch.

    I never hear any of the igniter clicks.

    I also never smell any gas, so the valve isn't opening. I guess that's good. I want to be able to troubleshoot the igniter without gas present.
     
  18. jjg

    jjg Member

    Messages:
    249
    Likes Received:
    2
    Joined:
    Jun 20, 2013
    Is there a little switch on the thermostat that needs to be turned on? I know on my hyroflame I have to turn the thermostat on and then the furnace (in that order) for it to work properly. I believe the switch is on the top of the thermostat.
     
  19. EdZilla

    EdZilla Member

    Messages:
    76
    Likes Received:
    10
    Joined:
    Sep 19, 2017
    Location:
    Denver
    My thermostat is a suburban and the switch is on the bottom. I know it's working properly. When I turn it on, the fan will come on. When i turn it off the fan will also turn off eventually.

    I'm starting to troubleshoot by looking at the voltages around the system. I obviously have 12V coming in because the fan comes on. The chassis appears to be ground. I exposed the DSI board by unscrewing it and see no voltage anywhere on it, whether the furnace switch is on or not so I'm wondering what powers the DSI board.

    I see 12v at what inthink is a relay. The right side of the furnace. See the photo below
     
    Last edited: Sep 21, 2017
  20. Fless

    Fless Active Member

    Messages:
    940
    Likes Received:
    191
    Joined:
    Aug 14, 2012
    Location:
    Colorado
    Make sure the 12v polarity is correct. The fan will run backwards if it's wrong, and the sail switch will never open. Don't ask me how I know....

    BTW, the fridge, on LP, does not use a "pilot". The teeny little flame is all it takes to make it work.
    _
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.