Page 1 of 3 123 LastLast
Results 1 to 13 of 27
  1. 01-06-2013, 04:53 PM #1
    ParamountAir
    ParamountAir is offline Professional Member
    Join Date
    Dec 2012
    Location
    Westerville, Ohio, United States
    Posts
    24
    Post Likes

    Janitrol gas valve voltage

    Issue with Janitrol furnace --

    Goes through normal sequence on call for heat - inducer on, pressure switch closes, HSI glows, then gas valve doesnt open. Interesting that the valve has 15-16V consistently until board calls for main valve to open, then 26V at the valve for a few seconds. The 15-16v is to chassis ground and ground on the valve terminal.

    I thought there would be no voltage on the valve until a call from the board, thoughts?
    Reply With Quote Reply With Quote
  2. 01-06-2013, 05:41 PM #2
    pacnw's Avatar
    pacnw
    pacnw is online now Professional Member*
    Join Date
    Dec 2007
    Posts
    7,554
    Post Likes
    safety or bad valve or loose connection or bad board or?
    The Food Stamp Program, administered by the U.S. Department of Agriculture, is proud to be distributing the greatest amount of free meals and stamps EVER.
    Meanwhile, the National Park Service, administered by the U.S. Department of the Interior, asks us to "Please Do Not Feed the Animals". Their stated reason for this policy "... the animals become dependent on handouts and will not learn to take care of themselves."
    from an excerpt by Paul Jacob in Sun City, AZ
    Reply With Quote Reply With Quote
  3. 01-06-2013, 05:45 PM #3
    Ductfisher's Avatar
    Ductfisher
    Ductfisher is offline Professional Member
    Join Date
    Jan 2013
    Location
    Central, FL
    Posts
    29
    Post Likes
    What is your inlet gas pressure? LP or Natural? If you have good inlet gas pressure and no outlet pressure when there is 24 volts across the gas valve coil then the gas valve is bad.
    Reply With Quote Reply With Quote
  4. 01-06-2013, 05:53 PM #4
    billg's Avatar
    billg
    billg is offline Professional Member*
    Join Date
    Dec 2004
    Location
    Caledonia WI
    Posts
    1,739
    Post Likes
    I think it's a bad valve.
    Reply With Quote Reply With Quote
  5. 01-06-2013, 06:14 PM #5
    Joehvac25's Avatar
    Joehvac25
    Joehvac25 is offline Professional Member*
    Join Date
    May 2012
    Location
    Upper Michigan
    Posts
    3,588
    Post Likes
    Double Check with the manometer the out let pressure. If you have 24v and no outlet pressure then well you get it. First verify you have inlet pressure though
    Reply With Quote Reply With Quote
  6. 01-06-2013, 06:26 PM #6
    VTP99's Avatar
    VTP99
    VTP99 is offline Professional Member
    Join Date
    Jan 2010
    Posts
    12,722
    Post Likes
    [QUOTE=ParamountAir;14929331]Issue with Janitrol furnace --

    Interesting that the valve has 15-16V consistently until board calls for main valve to open, then 26V at the valve for a few seconds.


    Something seems fishy here. Sounds like some kind of back feed. Are you sure your transformer is not weak ? I would think that the ignition board would not leak voltage till a call for the main valve. How many wires go to the valve ?
    Reply With Quote Reply With Quote
  7. 01-06-2013, 06:33 PM #7
    Joehvac25's Avatar
    Joehvac25
    Joehvac25 is offline Professional Member*
    Join Date
    May 2012
    Location
    Upper Michigan
    Posts
    3,588
    Post Likes
    [QUOTE=VTP99;14930031]
    Quote Originally Posted by ParamountAir View Post
    Issue with Janitrol furnace --

    Interesting that the valve has 15-16V consistently until board calls for main valve to open, then 26V at the valve for a few seconds.


    Something seems fishy here. Sounds like some kind of back feed. Are you sure your transformer is not weak ? I would think that the ignition board would not leak voltage till a call for the main valve. How many wires go to the valve ?
    I bet it's a false reading, one other thing is look for the cracks on top of hx
    Reply With Quote Reply With Quote
  8. 01-06-2013, 08:02 PM #8
    billg's Avatar
    billg
    billg is offline Professional Member*
    Join Date
    Dec 2004
    Location
    Caledonia WI
    Posts
    1,739
    Post Likes
    The coil in the gas valve is open, once you change it the 15-16 volts will go away and it will function when it gets 24 volts.
    Reply With Quote Reply With Quote
  9. 01-06-2013, 08:04 PM #9
    ParamountAir
    ParamountAir is offline Professional Member
    Join Date
    Dec 2012
    Location
    Westerville, Ohio, United States
    Posts
    24
    Post Likes
    Thread Starter
    Yes, definitely something fishy. I must have measured it started the unit 10 times and measured voltage to make sure my readings were correct. There are 3 terminals on the valve, MV, PV (factory jumped) and C. Where could the 15 volts be coming from?

    Thanks!
    Reply With Quote Reply With Quote
  10. 01-06-2013, 08:36 PM #10
    craig1
    craig1 is offline Professional Member
    Join Date
    Jun 2003
    Location
    Chicago, IL
    Posts
    6,063
    Post Likes
    Quote Originally Posted by ParamountAir View Post
    There are 3 terminals on the valve, MV, PV (factory jumped) and C. Where could the 15 volts be coming from?

    Thanks!
    the 15 volts is phantom voltage. When you have a wire connected to nothing (open relay on one end, broken gas valve on other) Voltage will be induced in it just by its proximity to other wires with current flowing in them.

    If you put any kind of load on the wire its voltage will drop to 0
    Reply With Quote Reply With Quote
  11. 01-06-2013, 09:00 PM #11
    chaard's Avatar
    chaard
    chaard is offline Professional Member*
    Join Date
    Jun 2006
    Location
    SW MO.
    Posts
    5,353
    Post Likes
    It's not uncommon to see the 24v split across the secondary of the transformer. 12v on one side to ground. 14v on other leg to ground. Together 26v when load is applied.
    Reply With Quote Reply With Quote
  12. 01-06-2013, 09:06 PM #12
    billg's Avatar
    billg
    billg is offline Professional Member*
    Join Date
    Dec 2004
    Location
    Caledonia WI
    Posts
    1,739
    Post Likes
    On Goodman common side of 24 volt transformer winding is grounded to chassis.
    Reply With Quote Reply With Quote
  13. 01-06-2013, 09:12 PM #13
    chaard's Avatar
    chaard
    chaard is offline Professional Member*
    Join Date
    Jun 2006
    Location
    SW MO.
    Posts
    5,353
    Post Likes
    I thought that after I posted. But it does happen, especially on 240v units.
    I have come across 2 different units that was 120v to ground on secondary side with no load. 24v with load. Still have never figured that out.
    Reply With Quote Reply With Quote
Page 1 of 3 123 LastLast
« Previous Thread | Next Thread »

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Forum Rules
Contracting Business

Related Forums

Plumbing Talks | Contractor MagazineThe place where Electrical professionals meet.
HPAC Engineering