I am a new owner, working my way through systems as we go. I have backwashed my FNS60 filter a few times but didn't have a proper tool for removing the drain plug (this item: Amazon.com : Pentair 190030 Drain Plug Cap Assembly Replacement Pool and Spa Filter : Outdoor Spas : Garden & Outdoor). Picked up a 7/8" ratchet and tried removing it this go round. Lots of gunk came out this way, good. N.b. this is a relatively new pool, and the builder nominally did a full cleaning of the filter a year ago (no witnesses). Since, I have not taken the filter apart, but have just backwashed until clear and replaced the DE. My filter is oversized and pool has stayed clean and pressures low.
All good until I tried to reinstall the plug. I noticed some debris on the plug threads, but initially didn't inspect closely (and now regret that). I carefully (but not enough) began to tighten, hand first then the wrench. When I got resistance I stopped, removed, and took a closer look at the plug. Turned out the debris was pretty tough and adherent Ca salt buildup. I scraped it off including some acid washing, and re lubed with Magic Lube. Tried to again carefully thread, no luck, keeps going off angle. On inspection, the plug threads are only slightly damaged; if the filter (female) threads were perfect, should thread fine. The damage is at the top of the plug, visible at the end of the 1st and 2nd go round of about 6 on the plug. the "deeper" threads are fine. I cant really see into the female threads of the filter body. Here's an image of the plug threads after clean up:
I'm guessing there's gunk at about the same level in the filter body threads, this is where it would settle in by gravity. Its possible the previous round of cleaning by others damaged the threads, don't know.
Does anyone have recs
1) current situation--seems I am at risk of further damaging the filter if I re-use this plug; is it good enough to start with a brand new plug? other thoughts/recs? Anyone for just powering it in and it will be fine?
2) the filter plug is relatively hard to access, any suggestions for a permanent fix that would be easier to access and not risk damaging the filter lower body every time a thorough backwash is done?--I found this thread for a Hayward filter (SOLVED: The threads are stripped on my Hayward sand filter - Fixya). Has anyone road tested something similar for FNS, and have very specific parts list (I'm not experienced in PVC repairs, so as specific as possible helpful).
Thanks very much!!
Ed
All good until I tried to reinstall the plug. I noticed some debris on the plug threads, but initially didn't inspect closely (and now regret that). I carefully (but not enough) began to tighten, hand first then the wrench. When I got resistance I stopped, removed, and took a closer look at the plug. Turned out the debris was pretty tough and adherent Ca salt buildup. I scraped it off including some acid washing, and re lubed with Magic Lube. Tried to again carefully thread, no luck, keeps going off angle. On inspection, the plug threads are only slightly damaged; if the filter (female) threads were perfect, should thread fine. The damage is at the top of the plug, visible at the end of the 1st and 2nd go round of about 6 on the plug. the "deeper" threads are fine. I cant really see into the female threads of the filter body. Here's an image of the plug threads after clean up:
I'm guessing there's gunk at about the same level in the filter body threads, this is where it would settle in by gravity. Its possible the previous round of cleaning by others damaged the threads, don't know.
Does anyone have recs
1) current situation--seems I am at risk of further damaging the filter if I re-use this plug; is it good enough to start with a brand new plug? other thoughts/recs? Anyone for just powering it in and it will be fine?
2) the filter plug is relatively hard to access, any suggestions for a permanent fix that would be easier to access and not risk damaging the filter lower body every time a thorough backwash is done?--I found this thread for a Hayward filter (SOLVED: The threads are stripped on my Hayward sand filter - Fixya). Has anyone road tested something similar for FNS, and have very specific parts list (I'm not experienced in PVC repairs, so as specific as possible helpful).
Thanks very much!!
Ed
