Page 1 of 2 12 LastLast
Results 1 to 13 of 14
  1. #1
    Join Date
    Oct 2005
    Posts
    9
    How do i test to see if the solenoid on a humidifier is getting a charge to operate and what sets off the solenoid to work either the stat or solenoid is not working on both furnaces after they have been replaced. The wires go to a fuel master (whatever that is??)

  2. #2
    Join Date
    Oct 2005
    Location
    Fairfax, VA
    Posts
    111
    A solenoid valve uses a simple coil of wire to magnetically operate the valve. When isolated from the circuitry, it will show continuity with an ohm meter ... although it will be something greater than zero.
    The voltage source is usually 24vac, which is switched by the humidistat and air flow switch, and often some safeties like high water, high temp etc. Different models have different components.

  3. #3
    Join Date
    Oct 2005
    Location
    Omaha, NE
    Posts
    309

    Turn on the Heating

    Set Humidistat at very high such as 50-60%,

    When furnace runs, the water should run from the drain pipe.

    If NOT:
    1. Problem with solenoid. Applying 24 volts across the 2 terminals should open it.

    2. Problem with Water supply: very often, over the years hard water deposits calcium etc. at the nipple orifice (where the saddle valve taps into the copper pipe). Better yet, a valve properly installed. The saddle valve is a "cut-corner" technique that many HVAC installers use. The opening is pin-hole size, and while it may serve the purpose for a few years, as time goes on the orifice becomes blocked with Calcium deposits etc.

    cn

  4. #4
    Join Date
    Oct 2005
    Posts
    9
    what is the best way to apply 24 volts across the solenoid(s). I think the water line is not clogged going or coming out of the solenoid as I checked and got alot of water in my face. Could the power have been cut off when the new furnaces were installed and how would I check that????

  5. #5
    First you need to know whether you have a 24-volt or 120-volt operated solenoid.

    But since they haven't worked correctly since the new furnaces were installed, WHY not call the installing HVAC Company to come out and have a look?

  6. #6
    Mod01 Guest

    Lightbulb

    jb:

    This is not a DIY site. Due to the site rules, we are unable to provide step-by-step troubleshooting procedures.

    It's time to call a pro. How about those guys that installed the furnace?

    Thanks, Mod01.

  7. #7
    Join Date
    Oct 2005
    Posts
    9
    I did and they said it was working fine.........I believe it is not since no water runs out when the furnaces are running like the previous years. I was not here when they made the call. They are very nice but seem incompetent. I paid alot for the new furnaces and hate getting into arguements, lifes to short etc etc Was wanting to atleast test the solenoids first, but will probably call them back?@#$%&^* My thought was if the solenoids are working and water flows when i test them, then it is a tstat/control problem.

  8. #8
    Originally posted by jbones
    I did and they said it was working fine.........I believe it is not since no water runs out when the furnaces are running like the previous years. I was not here when they made the call. They are very nice but seem incompetent. I paid alot for the new furnaces and hate getting into arguements, lifes to short etc etc Was wanting to atleast test the solenoids first, but will probably call them back?@#$%&^* My thought was if the solenoids are working and water flows when i test them, then it is a tstat/control problem.
    You can not gage whether your humidifier is working properly by looking to see if water is running when the furnace is running. Your humidifier can be wired to work in several ways. It can run during a call for gas, a call for fan only, or a call for heat (during gas valve and fan operation). Without knowing how your humidifier is wired, there is no use in speculating about its function right now.

    Where is your humidistat located?

    If on the return ductwork, is it mounted with a mounting plate around it and countersunk into the duct?

    What do you set your humidity to?

    Is your humidistat marked in percentages, such as 15, 25, 35, 45% or is marked by low, med, and high?

    Do you have another reputable humidity sensor in the house that is telling you the humidity is incorrect?

    Is this a bypass type humidifier? Is there a heat run connected to it and running to another portion of your ductwork?

    Can you give a make and model?

    (I'm not trying to give DIY step-by-steps here, just want to help this homeowner out and then recommend a pro if he needs it)


  9. #9
    Join Date
    Oct 2005
    Location
    Fairfax, VA
    Posts
    111
    When my humidifier is running, there is no problem hearing the water flow. If you turn up the stat for a call for heat, with the furnace running adjust the humidistat from low to high and listen. You should at least hear a click as the valve opens and closes. If so, the solenoid is functioning, but that doesn't mean the water passages are not clogged.
    I already explained how to check it with an ohm meter.
    If you hear the clicking but no water flow noise, it's just clogged.

    If you don't understand this stuff and don't trust the service company, you don't have much choice but to call someone else in.

  10. #10
    Originally posted by speedracer
    I already explained how to check it with an ohm meter.
    You should not be advising an untrained homeowner to perform electrical diagnostics on his humidifier with only a partial understanding of electrical theory and ohm's law. This is really responsible behavior.

  11. #11
    Join Date
    Oct 2005
    Posts
    9
    It is an aprilaire 600 Have it set to 50%, on ductwork with stat right next to it, when switch to test mode on both humidifiers no water runs out of either one. Lots of water ran last year out the drain etc. Is bone dry after the furnace switch out.................

  12. #12
    Senior Tech Guest
    As previously advised this is not a diy site. Pleeeeeeease call a pro.
    The fires are regenerating today...

  13. #13
    Originally posted by jbones
    It is an aprilaire 600 Have it set to 50%, on ductwork with stat right next to it, when switch to test mode on both humidifiers no water runs out of either one. Lots of water ran last year out the drain etc. Is bone dry after the furnace switch out.................
    Okay, so you have a Model 600. Without looking at my literature, I believe that is a bypass humidifier that uses a remote sensor to sense outdoor conditions and uses that to control your humidifier. These systems use an integrated control center to perform "LOGIC". My advice to you is this:
    - make sure the bypass damper is open
    - make sure the water valve is in the on position
    - make sure there is a new water panel in place
    - make sure you don't already have high humidity inside from some other source (buy yourself a quality humidity sensor)
    - then call a professional

    You didnt' answer any of my other questions about the mounting plate or the like, so I am really in no mood to continue my generosity of thought. This system is beyond simple troubleshooting. If you try, you could cause enough damage to it to warrant purchasing a new one. Call a pro.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event