Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 3 of 3

Thread: Sand filter backwash trouble

  1. Back To Top    #1

    Sand filter backwash trouble

    When I backwash, things run normal for about 20 sec then the pressure gage goes to zero and the water leaves the glass sight. What could be the problem?

  2. Back To Top    #2
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887

    Re: Sand filter backwash trouble

    Welcome to TFP!

    Either an air leak or a suction side blockage could cause that problem, but if either of those were the problem it should also fail when not backwashing. I suppose there could be something wrong with the multi-port valve.

    When you are having problems, does the pump sound change? Does the pump strainer basket fill with air? Do you notice anything else unusual happening.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  3. Back To Top    #3

    Join Date
    Jun 2007
    Location
    NC
    Posts
    255

    Re: Sand filter backwash trouble

    Quote Originally Posted by stacy71
    When I backwash, things run normal for about 20 sec then the pressure gage goes to zero and the water leaves the glass sight. What could be the problem?
    IT sounds like a torn/damages spider gasket in the multi-port valve, been there...

    Do you have any similar problems when vacuuming to waste or on a rinse?
    Triad Region of NC
    18x37 Vinyl IG (24,000 gal.), BBB & GoldLine AquaLogic PS4 SWG, Hayward 1 HP Superpump / Hayward Sand Filter / Polaris 280 cleaner / 6 deck jets / Sheer Descent Waterfall (in coping) / Brick Red Concrete Coping / Stamped Concrete Deck
    Lots of oak trees, maple trees, *and* leaves!

Posting Permissions

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