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Thread: No Check Valve - Should Jandy 3-way still allow back flow?

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    Join Date
    Apr 2015
    Location
    Lubbock, TX
    Posts
    9

    No Check Valve - Should Jandy 3-way still allow back flow?

    Hi All,

    We have a Jandy No-Lube 3-way that splits the return water between the pool and the spa. The spa sits higher than the pool. There is no check valve on the return line to the spa. After the pump turns off, the Jandy allows water to back flow from the spa and back into the pool until the water level in the spa falls below the level of the return jets. Is the Jandy supposed to allow this to happen?
    17,500 IG plaster, attached spa with spillover, Hayward Heat Pump 350k BTU, Whisper Flo 1.5h, Sand Filter, FAS-DPD 81329

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    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: No Check Valve - Should Jandy 3-way still allow back flow?

    Yes. You either need to close the spa off before the pump shuts off or install a check valve between the three way and the spa. It will let water flow into the spa but prevent it from siphoning down to the pool. Also note if you have both drains open, they'll siphon, too. I keep the spa drain normally closed and just let it fill and spill to keep the water in the spa fresh.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

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    Join Date
    Apr 2015
    Location
    Lubbock, TX
    Posts
    9

    Re: No Check Valve - Should Jandy 3-way still allow back flow?

    Thanks, Richard! That's what I thought, too.
    17,500 IG plaster, attached spa with spillover, Hayward Heat Pump 350k BTU, Whisper Flo 1.5h, Sand Filter, FAS-DPD 81329

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