Inserting the new filter cartidge into the Hayward spa or hot tub filter base (C) Daniel FriedmanHot Tub, Spa, Whirlpool Bath Filter Replacement
When to replace the Filter Cartridge Used in Spas / Hot Tubs & Whirlpool Baths

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Hot tub & spa or whirlpool bath filter replacement procedures:

Here we describe how often to replace the hot tub or spa filter and how to do so.

In these articles we describe the use, operation, maintenance as well as common problems, troubleshooting, & repair suggestions for hot tubs, spas, and whirlpool baths. We discuss hot tub leaks, broken hot tub or spa jets, hot tub or spa water temperature & heater repair, hot tub or spa pump diagnosis & repair, hot tub or spa filter maintenance, cleaning & repair, noisy air pumps at hot tubs, noisy water pumps at the hot tub or spa, and other hot tub, spa or whirlpool bath diagnosis & repair topics.

Page top photo, a Hawkeye Products hot tub or spa installed in Minnesota serving as an example of of repair & maintenance topics in this article. This spa was installed ca 1995 and is still in operation.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

When & How to Replace the spa/hot tub filter cartridge

Hot tub or spa filter cartridge inspection & replacement (C) Daniel Friedman

Replace the hot tub or spa filter cartridge if it looks black and slimy like the filter at left in our photograph below. Basically after cleaning your hot tub filter cartridge should be white.

If the filter cartridge is damaged or if it cannot be adequately cleaned, it should be replaced. The spa filter above is a Hayward CX 250F / H26 4. For this unit the replacement filter is identified as Hayward No. C-250-RE. Order Model No. Hayward Star Clear Filter Cartridge No. C-250 RE (for the filter unit shown in this article). Larger filter models for other Hayward Star-Clear filters include C-500 RE and C-750 RE.

That's enough data to buy a replacement filter when needed. The filter model is usually embossed on the plastic filter rim, or owners may keep filter packaging or make a note on the spa instruction sheets to make filter re-ordering easier.

To replace the hot tub or spa filter cartridge you'll need to unscrew the hand-screw at the top of the dome cap of the filter assembly. This Hayward spa and hot tub filter (below) is very widely used so parts and filters are usually readily available. Below you'll see that this particular Hayward spa filter was installed too close to the tub side, making both dome cap removal and filter removal/insertion difficult - but not impossible. Work with care to avoid damaging the filter during installation or removal.

Inserting the new filter cartidge into the Hayward spa or hot tub filter base (C) Daniel Friedman

Just below, I've seated the new filter cartridge inside the filter canister. You'll need to center the filter and press it down into place. When properly seated the bottom of the filter will press over a raised lip in the bottom of the filter canister so that it is centered and level.

New filter cartridge in place in the Hayward hot tub filter canister (D) Daniel Friedman

Below I'm checking the snugness of the hand screw that secures the dome top of the Hayward hot tub filter canister in place.

Tightening the hand screw on the dome cap of the Hawyard spa or hot tub filter canister (C) Daniel Friedman

Watch out: when replacing the filter cartridge and then the Star Clear spa / hot tub filter dome or top, the black filter top knob should be made hand tight enough to see no leaks around the top rim. Don't use a tool to tighten it or you'll break the unit.

Next dry off all sides of the filter canister, paying particular attention to the top screw, air bleeder, joint of cap to filter canister body, and any other fittings that might leak.

Dry off the hot tub filter to check for leaks (C) Daniel Friedman

After replacing the dome top and turning on the pump, check for leaks around the filter canister top at the hand screw knob, at the air bleeder (you may need to open the bleeder to remove air from the filter system, closing it when air stops exiting and water starts squirting all over the place), and at the joint of the dome top to the filter canister body.

Check for leaks at the hot tub filter air bleed screw (C) Daniel Friedman

After drying my hand I start feeling for leaks, first at the hot tub filter air bleeder screw (photo above). Remember to make this screw just finger tight; you shouldn't need a tool and if you over-tighten it you may damage plastic parts.

Check for leaks at hot tub filter cartridge cap screw (C) Daniel Friedman

Above: I'm feeling for water around the hand-screw that secures the dome cap in place on the hot tub or spa filter cartridge. If I properly dried-off the filter assembly after installing the cap and tightening the screw, now my finger will come away dry.

Checking for leaks around the bottom of the cap of the hot tub filter assembly (C) Daniel Friedman

Above: I'm checking that the dome cap is not leaking at its mating surface with the hot tub canister filter body. If my finger comes away wet I dry off my hand and also the cap to filter body joint again with a dry towel, turn on the hot tub pump, and check again.

Instructions for Jetted and Soaking Tubs


Continue reading at SPA / HOT TUB PUMP OPERATION, or if your spa or hot tub needs repair see SPA HOT TUB WHIRLPOOL REPAIRS or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see these

Article Series Contents

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