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  1. #1
    Join Date
    Feb 2006
    Location
    michigan
    Posts
    177

    Question

    I recently installed a 2-stage variable speed Amana amv90905dx upflow furnace. The home has a single stage stat so I had the power off and adjusted the pin accordingly for a single stage stat. I also jumpered w1 & w2. My problem is that the furnace fires up right to high fire and skips low fire. Wondering if anyone had run into this and how to fix.

  2. #2
    Join Date
    Feb 2006
    Posts
    360
    Jumper sounds like the problem to me. I know Trane 2 stage furnaces work off a timer on the furnace control board and 1st stage will run no matter if 2nd is calling or not for 10 minutes and then switch to 2nd stage. Don't know who makes the Amana control board but it is probably set up to run 2nd stage when called with no time period for 1st stage. Having 1st and 2nd stage jumped will run 2nd stage all the time. Thats just my thoughts on it.

  3. #3
    Join Date
    Feb 2006
    Posts
    360
    Just to get more specific, if W1 and W2 are jumped on a white rodgers 50A51 board there is a 10 minute timer before inducer motor goes into high speed, closes high diaphram pressure switch and enegizes 2nd stage of gas valve and then ups the speed of the motor.

  4. #4
    Join Date
    Feb 2006
    Location
    michigan
    Posts
    177
    So if I take off the jumper, then it should start on low fire then go to high fire(after the 10 min I set it for)?

  5. #5
    Join Date
    Feb 2006
    Posts
    360
    No. If you take the jumper off then it will only go into 1st stage and not 2nd stage ever. From what I think is going on, your only solution is to get a 2 stage heat / 1 stage cool thermostat to get the multi-stage gas furnace. I am not that familiar with Amana products so I am jsut taking an educated guess here without being able to look at the furnace

    Is this for your home?

  6. #6
    Join Date
    Feb 2006
    Location
    michigan
    Posts
    177
    No it is for a cutomer. But isnt that the whole concept of the pin selector on the control board? So that if you have a single stage stat with a two stage furnace you can still achieve dual staging. I was under the impression that if I had the pin in the single stage posistion, then it would fire on first stage for ten minutes then go to second stage after that.

  7. #7
    Join Date
    Feb 2006
    Posts
    360
    yeah, thats what it would seem like. check your inducer motor speed and pressure switches. inducer motor is what makes it goe into 2nd stage anyways so check that out to make sure the board is letting it start in low speed. besides that, i'm not sure what else to tell you to check.

  8. #8
    Join Date
    Feb 2006
    Location
    michigan
    Posts
    177
    ok i'll try that. thanks for the info.

  9. #9
    Join Date
    Feb 2005
    Posts
    70
    you need to remove the jumper wire from w2 and set the pin for single stage stat,also check the time delay you have a choice of 5 or 10 minutes

  10. #10
    Join Date
    Mar 2005
    Location
    burlington county n.j.
    Posts
    9,723
    never saw amana 2 stage but with lennox if you jump w1-w2 you will only get high fire. take out jumper.

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