Hot Spot OEM 31114 spa filter (C-8465)

Hot Spot (Hot Spring family)

Replacement numbers

Unicel C-8465, Pleatco PWK65

Fits Hot Spot OEM 31114, 71827, 71828.

Diameter 8-1/2" (216 mm)Length 10-1/2" (267 mm)65 sq ft4 models listed

Disclosure: we may earn a commission from qualifying purchases made through retailer links on this site, at no extra cost to you. As an Amazon Associate I earn from qualifying purchases. Check price on Amazon opens the Unicel C-8465 listing we checked. These are affiliate links. Product photos are omitted unless Amazon supplied one through the Product Advertising API or a SiteStripe image link. Verify dimensions before ordering. Each “Check price on Amazon” button opens a specific listing whose title we checked. The line under the name repeats only that title. See our affiliate disclosure.

UnicelC-8465
PleatcoPWK65
FilburFC-3960
Top3" (76 mm) / open
Bottom3" (76 mm) / open
Ø 8-1/2" (216 mm)10-1/2" (267 mm)Side view · end views belowTopBottom
Top: 3" (76 mm) / open
Bottom: 3" (76 mm) / open
Drawn to scale from the listed diameter and length and open-end sizes. Handles, threads and closed ends are drawn as symbols, not to scale. 65 sq ft media.

Request a filter replacement reminder

This stores a request for this filter: the model, the date you installed it, and how often you replace it. Submitting stores the request and does not send email.

We'll only use your email for this request.

Deletion requests go only to the address on the privacy page.

For Hot Spot, C-8465 cartridge (OEM 31114) sits in Hot Spot (Hot Spring family). The cross-reference prints OEM 31114, 71827, 71828; Unicel C-8465; Pleatco PWK65; Filbur FC-3960. 8-1/2" across, 10-1/2" long, top 3" / open, bottom 3" / open, 65 sq ft.

31114 carries this note from the catalogs: Unicel lists these OEM numbers under Hot Springs Spas; Hot Spot model fitment is from Leisure Time Inc.

Model list attached to C-8465 cartridge (OEM 31114): Hot Spot La Palma, years 2008–2009, listed by Leisure Time Inc. dealer listing; Hot Spot Relay, years 2010–2026, listed by Leisure Time Inc. dealer listing; Hot Spot Rhythm, years 2011–2026, listed by Leisure Time Inc. dealer listing; Hot Spot Tempo, years 2010–2019, listed by Leisure Time Inc. dealer listing.

Before ordering C-8465, compare it with C-7350 differs by Unicel C-7350, Pleatco PCD50N, Filbur FC-3963, 7" diameter, 10-3/4" long, top semi-circular handle, bottom 2-11/16" / open, 50 sq ft, OEM 1019401, note says Unicel lists these OEM numbers under Caldera Spas; the Hot Spot Sorrento fitment is from Leisure Time Inc.; Leisure Time Inc.: For a 2024 Makena, confirm the spa serial number before ordering. Other Makena years use a different cartridge.; and C-6430 differs by Unicel C-6430, Pleatco PWK30-4, Filbur FC-3915, 6" diameter, top 1-15/16" / open, bottom 1-15/16" / open, 30 sq ft, OEM 31489, note says Unicel lists these OEM numbers under Hot Springs Spas and directs Hot Spot owners there; Hot Spot model fitment is from Leisure Time Inc.; Leisure Time Inc.: Use this pleated cartridge only where the spa specifies 71825 or its listed equivalent. Models requiring Tri-X cartridges must use the appropriate Tri-X filter.; Leisure Time Inc.: Replaces compatible 71825 or 31489 pleated cartridges. Models requiring Tri-X cartridges must use the appropriate Tri-X filter. Unicel's 2026 price list (not its spec table, which still prints C-6430 with 4 oz media) says "C-6430 USE C-6430AM", the antimicrobial version (30 sq ft, Watkins replacement)..

Where those figures are printed: Unicel 2026 Replacement Guide on C-8465 (OEM cross reference (Hot Springs Spas section), PDF p.39 (printed p.35); spec table PDF p.21 (printed p.17)). Pleatco 2023 Catalog on C-8465 (Unicel-to-Pleatco cross reference, PDF p.47). Filbur Catalog & Reference Guide on C-8465 (Product by Pool/Spa Manufacturer (OEM), Hot Springs, printed p.38 (PDF p.20)). Leisure Time Inc. (Hot Spring/Caldera dealer) on C-8465 (Compatibility section: model and model-year list). Leisure Time Inc. (Hot Spring/Caldera dealer) on C-8465 (Compatibility section: model and model-year list).

Hot tubs listed for this cartridge

Model / systemYearsListed by
Hot Spot La Palma2008–2009Leisure Time Inc. dealer listing
Hot Spot Relay2010–2026Leisure Time Inc. dealer listing
Hot Spot Rhythm2011–2026Leisure Time Inc. dealer listing
Hot Spot Tempo2010–2019Leisure Time Inc. dealer listing

Other Hot Spot models and years are in the Hot Spot section of the Hot Spring filter by model and year lookup.

Check the cartridge you removed

Measure diameter, length, and both ends, then compare them with the figures above. The steps are in the measuring guide. Why the bottom decides whether it seals: open-end vs threaded filters. Power, the retainer, and not running the spa empty: how to install a cartridge. Brand notes: Hot Spring filter sizes by collection. Number formats: how Filbur, Unicel and Pleatco numbers compare.

The same C-8465 number is also on the Hot Spring, Caldera pages.

Other Hot Spot cartridges

All 5 Hot Spot spa filters

Every number on this row, on one screen: cross-reference lookup. Published clean and replace intervals for this cartridge, and a buy link for the numbers above: replacement schedule and reorder. The interval comparison by brand: calculator.

Cleaner and test strips

Hose rinse and soak steps are in how to clean a cartridge. Named cleaners and strips are in filter cleaners and test strips.

Filter cleaner and test strips

Sources