I've seen quite a few posts on this topic and don't know if mine is covered in them or not. I have a Hayward C900 and I can't get the lid off. As I turn the knob, it loosens for a few turns and then the knob pops, and no more loosening. I'm thinking its stripped but really have no way to check because I can't get the lid off. Anyone have any ideas?
Hayward C900 Filter Cap Stuck
- Thread starter ktick13
- Start date
- Jun 22, 2014
- 52,015
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Welcome to TFP! 
Your C900 is probably much like my C1200. See the links below for some tips that may help.
www.troublefreepool.com
www.troublefreepool.com
Your C900 is probably much like my C1200. See the links below for some tips that may help.Hayward C1200 Stripped Locking Knob/Rod Fix
Moved from here. filter has one year warranty. seen similar models where the tightening rod loosen from the bottom debris sump (usually from overtightening and/or lack of top lid O ring lubrication?) rod is probably intact so either the bottom or top female threads may be messed up. if...
www.troublefreepool.com
Hayward Cartridge Filter Locking Knob Repair
(UPDATED 11 Mar 2021) The following was used on my Hayward C1200, but may also apply to other Hayward-series cartridge filters that utilize the locking knob on top. These procedures should help those who find that their locking knob on top doesn't seem to fully disengage from the threaded rod...
www.troublefreepool.com