Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 5 of 5

Thread: Jandy LT heater question...

  1. Back To Top    #1

    Jandy LT heater question...

    Hi, I have a Jandy LT 400N-L pool heater and it stopped working the other day.

    The "pressure switch" red light was blinking, so I assumed the old pressure switch was bad (after removing it to make sure there was a steady stream of water coming from the copper tube - which there was) and replaced it (I actually forgot which wire went where - I figured the white wire went to the common connection on the switch, which I hope is right...).

    Anyways, after connecting the new switch, it still didn't fire up and the red "pressure switch" light was still blinking.

    I tried removing the white wire coming from the switch and jumped it over on the block (as shown in the first picture), and the blower fired up and then the heater came on.

    I then removed the wire and put it back to the normal position on the block (as shown in the second picture), and everything shut down.

    Anyone have any ideas what's up? Any feedback would be greatly appreciated!

    Thanks.
    Attached Images Attached Images

  2. Back To Top    #2
    gtemkin's Avatar
    Join Date
    Jun 2008
    Location
    Seattle, WA
    Posts
    738

    Re: Jandy LT heater question...

    It shouldn't matter which wire goes to which pressure switch connection. It's just a basic on-off switch that doesn't care which way electricity flows through it.

    Your troubleshooting of moving the white wire to the top of the terminal block, and then having things function, points to the problem being in the circuit connected to the left side of the terminal block; the red and black wires that are crimped to the white wire stubs. Do the red and black wires go to a timer or after-run contacts attached to a timer? I think that's the source of your problem.
    21K gal 16' x 40' in-ground pool built 1959, old school with Jacuzzi bronze pump, American Products 24" Sand Filter & Americana Multiport valve, Jandy Lite2 millivolt heater, Coverstar cover, and classic Kreepy Krauly.

  3. Back To Top    #3
    gtemkin's Avatar
    Join Date
    Jun 2008
    Location
    Seattle, WA
    Posts
    738

    Re: Jandy LT heater question...

    When I blew up your photo's it was obvious the installer (apologies if it was you) came from the school of making crimp connections with whatever hammer/chisel/vise-grips/pliers was closest at hand. If it was my heater, I'd cut the red and black wires off where they enter the blue splices and re-terminate those wires direct to the left side of the terminal block with properly crimped fork tongue terminals. There's no need to have those little white stub wires and the extra crimps in the electrical path.
    21K gal 16' x 40' in-ground pool built 1959, old school with Jacuzzi bronze pump, American Products 24" Sand Filter & Americana Multiport valve, Jandy Lite2 millivolt heater, Coverstar cover, and classic Kreepy Krauly.

  4. Back To Top    #4

    In the Industry

    ps0303's Avatar
    Join Date
    Jul 2011
    Location
    FL
    Posts
    3,435

    Re: Jandy LT heater question...

    You obviously have a control system which is the black and red wires on the other side of the terminal block. To eliminate the control system from the equation, you can remove those two wires and then connect those two terminals with a wire. Now see if the system works.

    Also, how clean is your filter? Even though you see water coming out of the copper tube where the pressure switch is connected, it might not me enough pressure to activate the switch.
    Paul
    http://www.gastekservices.com A word of caution: When working with gas and electrical you might want to consider a licensed contractor. Consider the value of your life and others around you. If you would like to provide a review of the help I provided, please use the following link to leave a review. gastek - Google Search,

  5. Back To Top    #5
    gtemkin's Avatar
    Join Date
    Jun 2008
    Location
    Seattle, WA
    Posts
    738

    Re: Jandy LT heater question...

    Quote Originally Posted by ps0303
    You obviously have a control system which is the black and red wires on the other side of the terminal block. To eliminate the control system from the equation, you can remove those two wires and then connect those two terminals with a wire. Now see if the system works.

    Also, how clean is your filter? Even though you see water coming out of the copper tube where the pressure switch is connected, it might not me enough pressure to activate the switch.

    He already performed the test you're suggesting and also proved that he had enough pressure, when he moved the white wire to the top left as shown in the first photo. That's when the heater fired up properly, proving the pressure switch was sensing pressure and completing the safety circuit.

    The problem is with whatever the red and black wires are connected to (or the suspect crimp connections to the red and black wires).
    21K gal 16' x 40' in-ground pool built 1959, old school with Jacuzzi bronze pump, American Products 24" Sand Filter & Americana Multiport valve, Jandy Lite2 millivolt heater, Coverstar cover, and classic Kreepy Krauly.

Posting Permissions

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