Solenoid Failure?

Discussion in 'Electrical Forum discussion & Blog' started by Kiko, Nov 16, 2011.

  1. Kiko

    Kiko New Member

    Messages:
    175
    Location:
    Royal Oak, Michigan
    My parents had a ventless gas log system installed in their fireplace 3 yrs ago, purchased from Lowes. The main burners are ignited by a solenoid located in the gas valve. This solenoid is powered by a remote controlled receiver box wired to the solenoid, which takes 4 AA batteries (six volts).

    The burners stopped working and did not work even after fresh batteries were installed in the remote and the receiver. I disconnected the wires to the solenoid and used my voltmeter to check the voltage coming from the box. It read 6 volts in both the "on" and "off" positions, which means the solenoid should be able to open and close, if working properly. I then touched the solenoid wires to the terminals of a 9 volt battery, and the solenoid opened and closed and the burners turned on and off.

    I lined up 5 AA batteries (7.5 volts) and the solenoid still worked fine. However, when I removed one of the batteries, the solenoid turned off the burners but would not turn them on unless I increased the voltage.


    I have four questions:

    1. Why would the solenoid work in one direction, i.e., close, but not open, with 6 volts?

    2. Why would increasing the voltage to 7.5 volts allow it to open and close, when it is designed to open and close with 6 volts?

    3. Does a solenoid wear out slowly, or does it go all at once?

    4. Is there a way to add an additional battery to the receiver, so I don't have to mess with trying to replace the solenoid, if the solenoid is defective?
    Last edited: Nov 16, 2011
  2. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    1. Why would the solenoid work in one direction, i.e., close, but not open, with 6 volts?
    I would guess that it would close without any voltage but not being familiar with the unit I can’ say. I have a gas heater that shuts off the gas during any power failure.

    2. Why would increasing the voltage to 7.5 volts allow it to open and close, when it is designed to open and close with 6 volts?
    It could be due to an increased resistance in the winding

    3. Does a solenoid wear out slowly, or does it go all at once?
    It can go either way, slowly or all at once

    3. Is there a way to add an additional battery to the receiver, so I don't have to mess with trying to replace the solenoid, if the solenoid is defective?
    I am not sure that this would be a good idea
  3. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,990
    Location:
    New England
    Some valves have a spring in them, so that can help (often to turn it off) one direction verses the other. It depends on the design. To save power, in this application, it probably swaps the voltage, and it stays (i.e., isn't sprung). The gaskets or bearing that the valve slides through could be worn or corroded.
  4. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,107
    Location:
    Houston, TX
    If you are only getting 6 Volts from 4 AA Batteries,
    Then your batteries are not all that Fresh.

    Good Alkaline batteries will be higher than 6.

    1.5 V No Load => 50% Dead
  5. Kiko

    Kiko New Member

    Messages:
    175
    Location:
    Royal Oak, Michigan
    I was just trying to keep things simple. The four brand new alkalines measured ~6.6 V.
  6. Kiko

    Kiko New Member

    Messages:
    175
    Location:
    Royal Oak, Michigan
    The way the receiver box works is that it puts out current in one direction to open the solenoid and reverses the current to close it. I assume this would cause the electromagnet to open and close some kind of ferrous "gate," possibly separate from the valve itself, since the gas valve is maintained in the "open" position at all times with only the pilot flame burning.

    Not sure if a spring is involved. My uneducated opinion is that the windings are okay, since the solenoid works in one direction. Perhaps the "gate" gets stuck when trying to open it because something is worn or corroded (as you mentioned.)
    Last edited: Nov 16, 2011
  7. Kiko

    Kiko New Member

    Messages:
    175
    Location:
    Royal Oak, Michigan
    One final thing. At some point in this "experiment," I wire-nutted in a couple of additional feet of 18 gauge wire to allow the remote box to sit outside of the fireplace (so I wouldn't have to bend over so much).

    How can I determine the voltage drop caused by that additional wire?
    The initial voltage is 6.6 volts DC and the wire gauge is 18. I don't know what the amperage or the wattage is, but I assume a 6V DC solenoid has a certain wattage rating. I just can't find it.
    Last edited: Nov 17, 2011
  8. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,107
    Location:
    Houston, TX
    Without knowing the current then you would just have to measure the Voltage.

    I don't think that it would be very much, If you just added a couple feet.

    Is it possible that your control box has a bad capacitor in it ?
    If it has one you may want to check it.
  9. BobL43

    BobL43 DIY Senior Member

    Messages:
    1,792
    Location:
    Long Island, NY
    It can't be much current that is drawn, otherwise the battery life would be very short. I have a Vanguard unvented gas firelog that uses a 9 volt battery in the receiver/control and it lasts for several years. Seems unsafe that it would require a voltage to close the (main burner?) valve. the pilot valve is kept open by a themocouple pilot generator device. Hmmm. did you try to contact the manufacturer of this unit?
  10. Kiko

    Kiko New Member

    Messages:
    175
    Location:
    Royal Oak, Michigan
    The box is fine. It puts out 6.6 volts in both positions.
    To measure the voltage at the other end requires unbolting the unit from the fireplace floor and removing all the logs to get to the solenoid.
    Last edited: Nov 17, 2011
  11. Kiko

    Kiko New Member

    Messages:
    175
    Location:
    Royal Oak, Michigan
    The manufacturer is Pro Com, and they haven't been very helpful in either diagnosing the problem or sending replacement parts (still under warranty.)

    The remote/receiver is made by SkyTech and they don't make a 9 volt receiver.

    I bought some battery holders and may try to add an additional AA battery or replace them all with a 9 volt and see if that will work. I may also just replace the remote with a rocker switch hooked up to a 9 volt if I can find one that puts out current in both the on and off positions. BTW, is there a special name for a switch like that? The good folks at Radio Shack never heard of one.
  12. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,990
    Location:
    New England
    An on/off switch just opens in the off position, otherwise, it wouldn't be an on/off switch.

    What likely happens in what you have is they swap the polarity of the voltage in one position verses the other, and in the 'off' position, it disconnects it entirely; otherwise, the circuit would be drawing power all the time, and the battery life would be lousy.

    Is it a rocker switch, with a 'center' position?
  13. Kiko

    Kiko New Member

    Messages:
    175
    Location:
    Royal Oak, Michigan
    The box has three positions: On, off, and remote. When you slide the switch to "on" it puts out 6.5 volts for two seconds to open the solenoid. When you slide it to "off" it swaps polarity and puts out 6.5 volts for two seconds to close the solenoid. In the "remote" position it does the same thing using the remote control buttons to switch on and off. Since it only draws current for a couple of seconds, the batteries last a year or more.
  14. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,990
    Location:
    New England
    It's likely a simple switch, but it's an input to an active circuit...i.e., there's a chip in there that's setting up the timing and likely the voltage polarity swap. You can duplicate the function, but it would be up to you to manually make the requried on/off pulse. Keep buggin the manufacturer, as they're the best source to help, especially if it is still under warranty.
  15. Kiko

    Kiko New Member

    Messages:
    175
    Location:
    Royal Oak, Michigan
    I've been dealing with the manufacturer for three weeks now, and they keep finding new hoops for me to jump through.

    My idea of adding an additional battery in series with the others may work, but I'm not sure if the added currrent will fry the circuit board.
  16. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    The circuit board will not pull any more current than what it is designed to draw but the added voltage will cause damage.

    Given what you are working on it might be better to have some qualified in the field to work on it than try to do something that it is not designed to do and end up with something that wont work or might even be dangerous.
  17. BobL43

    BobL43 DIY Senior Member

    Messages:
    1,792
    Location:
    Long Island, NY
    I agree with JW; as much as we would like to figure out how everything works and fix everything ourselves, sometimes, especially with gas and fire appliances, its not worth it and is very dangerous. Get a gas tech there and let him diagnose it. Problem is, he'll probably tell you to replace the whole gas log; I hope not.
  18. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,607
    Location:
    Cave Creek, Arizona
    A "battery operated valve" HAS to be powered into the on or off position, using some kind of "latching mechanism" to hold it in position. IF the battery had to maintain in in the "ON" position and it defaulted to "OFF" without power the batteries would die in a matter of minutes, or hours, but ALWAYS within a relatively short time frame.
  19. BobL43

    BobL43 DIY Senior Member

    Messages:
    1,792
    Location:
    Long Island, NY
    That does make a lot of sense to me, and I realized that, BUT, if the firelog is lit, and the battery "just happens" to weaken to the point where it does not have enough power to shut off that flame when you want to shut it off, that would require the owner reaching into the fireplace and turning the manual valve knob to "pilot" or "off". May not be extremely dangerous (it is easy to do it though), but it seems like an odd design.

    These non vented fireplace logs have an oxygen depletion sensor normally (at least mine does). Would a dead battery prevent the system from shutting down if needed? The pilot has its own millivolt safety system, but I really have not looked into what other safeties are built into these fireplace units. I guess the AGA certifies them all. Well, Canada now may have that responsibilty. All this thread is about the units with a remote control, lke the OP and the one I have, so I guess on a fireplace that is stricly manually controlled by the manual gas valve knob works on the millivolt current going through safeties like any other similar system? I'm interested in learning here too.
  20. Kiko

    Kiko New Member

    Messages:
    175
    Location:
    Royal Oak, Michigan
    Turning the solenoid off seems to require a lot less voltage than turning it on. So, if the battery started to get weak, you would (in theory) be able to shut the burners, without being able to turn them back on. In fact, that's my whole problem. The latch, which is activated by the solenoid, closes no matter what kind of batteries I use. However, even after I wired a 9 volt to the 6 volt receiver box, the latch eventually got stuck again when I tried to turn on the burners.

    Short of hooking up a car battery to the solenoid, :eek: I'm fresh out of ideas and will have to wait for the new parts to come... unless there's a way to take the solenoid apart and lubricate the latch or replace the spring??
    Last edited: Nov 19, 2011

Share This Page