Hayward CX900W Star-Clear Plus filter knob washerHayward Star-Clear Plus Knob Washer, CX900W In stock$1799
Hayward CX900W Star-Clear Plus filter knob washer
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Hayward Star-Clear Plus Knob Washer, CX900W

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$1799
In stock
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Quick overview

  • Genuine Hayward The factory CX900W knob washer.
  • Two required A filter takes two of these washers, so order in pairs.
  • Star-Clear Plus range Listed for the C751, C900, C1200, C1750 and C1900 cartridge filters.
  • Also Pro-Grid separation tanks Used on the DE-900 and DE-1100 separation tanks as well.
  • Sits under the clamp knob It spreads the load where the knob bears on the clamp.
  • Cheap part, real job A missing washer lets the knob chew into the clamp and never quite seal.
Full description and specifications ↓

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Product details

The Hayward CX900W is the knob washer used on Star-Clear Plus cartridge filters and Pro-Grid DE separation tanks. It is the genuine Hayward part.

Where it goes

The washer sits under the clamp knob and spreads the load where the knob bears down. It is a small piece, but without it the knob presses directly on the clamp, which means the clamp never draws evenly and the filter head does not seal the way it should.

Order two

Hayward specifies a quantity of two, so a filter needs a pair. If you are chasing a leak at the clamp, look at the filter head lid o-ring and the knob o-ring while you are in there, because a clamp area leak is usually one of those three parts.

Specifications
Brand Hayward
Manufacturer part number CX900W
UPC 610377209304
Type Knob washer
Part type Pool filter part
Quantity required 2 per filter
Fits Hayward Star-Clear Plus C751, C900, C1200, C1750 and C1900 cartridge filters
Also fits Hayward Pro-Grid DE separation tanks DE-900 and DE-1100
Shipping weight 0.02 lb
Ships Parcel

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Questions and answers

What people ask about this product, answered by our pool techs.

How many do I need?
Two. Hayward calls for a quantity of two per filter, so order a pair.
Which filters use it?
The Star-Clear Plus C751, C900, C1200, C1750 and C1900 cartridge filters, and the Pro-Grid DE-900 and DE-1100 separation tanks.
Is it a genuine Hayward part?
Yes. It is the Hayward OEM part, number CX900W.
My filter leaks at the clamp. Is this the fix?
It can be part of it. A missing or crushed washer stops the knob from drawing the clamp down evenly. Check the head lid o-ring and the knob o-ring at the same time, since a clamp leak is usually one of the three.
Ask your own question