Dirty Water From Jetted Tub Jets: How to Clean a Whirlpool Tub

Posted by

Few things spoil a relaxing soak faster than turning on the jets and watching flakes of black or gray gunk swirl into clean bathwater. Jetted tub cleaning is one of the most overlooked chores in a home, and dirty water from the jets is a common finding when we test whirlpool tubs during home inspections in Fargo, Moorhead and West Fargo.

This guide explains why jetted tubs get dirty, the signs to watch for, what this finding means in an inspection report, how to flush and clean the jets, and how to keep the problem from coming back.

Why jetted tubs collect dirt in the pipes

A jetted tub (also called a whirlpool tub or hydromassage tub) has a pump that pulls bathwater through a suction fitting, pushes it through a loop of plumbing behind the tub, and sends it back out through the jets. That plumbing is the problem. It never fully drains.

After every bath, a little water stays trapped in the pump, the pipes and the jet bodies. That water carries body oils, soap and bath product residue, skin cells and minerals. In a dark, damp pipe, it becomes food for bacteria and fungi, which build up as a slimy film called biofilm on the inside of the plumbing. The next time the jets run, the moving water breaks loose pieces of that film and blows them into the tub.

How much is in there? A Texas A&M University microbiologist, Dr. Rita Moyes, tested water from 43 whirlpool bathtubs in homes and hotels. Every tub had microbial growth. Most had bacteria from the gut, 81 percent had fungi, and about a third had staph bacteria. She noted that the moving water creates a mist that can carry these organisms into your lungs.

Tubs that sit unused are the worst. In many homes the jetted tub in the primary bathroom gets used a few times a year, and in a vacant or for-sale house it may not have run in months. The longer water sits in the lines, the more buildup there is when the jets finally turn on.

Signs your jetted tub needs cleaning

  • Black, brown, gray or white flakes in the water after the jets start
  • Cloudy or discolored water that was clear before the jets ran
  • A musty, sour or mildew smell when the pump starts
  • Slime or residue on the jet faces or inside the jet openings
  • A ring of scum on the tub that returns quickly after cleaning

What dirty water from jets means in an inspection report

When a home has a jetted tub, we fill it above the highest jet and run the pump to see that it starts, the jets move water and the controls work. If dirty water or debris comes out of the jets, we note it in the inspection report and recommend cleaning the system before use.

On its own, this is a maintenance item, not a sign of a failed tub. It usually means the tub has not been used or flushed in a while. Other findings at a jetted tub are different and may need a repair:

  • Jets that do not move water, or will not turn or adjust. Jets can stick from mineral buildup or a failed part.
  • No access to the pump. Electrical codes call for the pump motor to be accessible, usually through a removable panel on the tub apron or from a nearby closet or room. Without access, the pump and its connections cannot be checked or serviced.
  • Missing GFCI protection. Hydromassage tubs must be protected by a ground-fault circuit interrupter (GFCI) under the National Electrical Code. If the circuit is not protected or the GFCI does not trip, have a licensed electrician correct it.
  • Leaks. A leak from a pump fitting or jet seal can soak the subfloor or the ceiling below without showing in the bathroom.

If you are buying a home, a dirty jetted tub is an easy item to handle after closing. If the pump does not run, leaks or lacks GFCI protection, get a repair estimate during your inspection contingency.

How to clean jetted tub jets

Always start with the manufacturer’s care instructions for your tub. Many tubs have the brand and model on a label near the pump, and most manuals are available online.

Kohler’s homeowner instructions for its whirlpool baths are a good example of a typical flush:

  1. Turn the jet air controls to the closed position so the jets do not draw in air.
  2. Fill the tub with warm water to at least 2 inches above the highest jet.
  3. Add 2 teaspoons of low-foaming powdered automatic dishwasher detergent and 20 ounces of regular household bleach.
  4. Run the jets for 5 to 10 minutes, then turn them off and drain the tub.
  5. Refill with clean water above the jets and run the jets for a few minutes to rinse the lines, then drain.
  6. Rinse and wipe the jets, faucet, drain and tub surfaces, and dry them with a soft cloth.

A few cautions:

  • Use low-foaming detergent only. Regular dish soap, bubble bath and shampoo foam heavily in a running whirlpool and can overflow the tub.
  • Never mix bleach with other cleaners. Bleach combined with ammonia or acidic cleaners such as vinegar releases toxic gases. Rinse the system completely between products.
  • Skip abrasives. Kohler warns against brushes and scouring pads on tub surfaces, and against letting cleaners soak on the finish.

If a lot of debris comes out on the first flush, repeat the process until the water stays clear. Removable jet trim rings and the suction cover can be taken off and scrubbed with a soft brush. For heavy mineral scale on small air jets, Kohler suggests a small between-the-teeth brush and white vinegar, used on its own, never with bleach.

If several flushes do not clear the water, the jets do not run, or you notice a leak, call a plumber or a whirlpool tub service technician.

How to prevent dirty water from jets

  • Flush on a schedule. Kohler recommends flushing its whirlpool systems twice a month or more, depending on use.
  • Flush before the first bath in a home you just bought, and any time the tub has sat unused for weeks.
  • Run the jets only with water above them. Manufacturers call for water at least 2 inches above the highest jet whenever the pump runs.
  • Go easy on bath oils, salts and bubble bath when using the jets. Residue from these products feeds buildup in the lines.
  • Keep the bathroom dry. Run the bath fan during and after bathing so moisture does not linger in the room or around the tub.

Jetted tub cleaning: common questions

Is dirty water from jets dangerous?

It is worth taking seriously. The buildup can contain bacteria and fungi that the jets spray into the water and the air above the tub. Clean the system before anyone uses it. Dr. Moyes, who led the Texas A&M study, noted that young children, older adults and people with weakened immune systems should not be exposed.

How often should I clean my jetted tub?

Follow your manufacturer’s schedule. Kohler, for example, recommends flushing twice a month or more depending on use, and always after the tub has sat unused.

Can I use vinegar instead of bleach?

Vinegar helps with mineral scale but is not a disinfectant like bleach. Use the products your manufacturer recommends, and never combine vinegar and bleach in the same fill.

Will the home inspector test my jetted tub?

During a Nordic inspection, we run accessible jetted tubs when they can be safely filled and operated, and report on the jets, the pump access, GFCI protection and any leaks we can see. Learn more about our home buyer inspections and our homeowner inspections.

Sources

Back to Blog