I'm a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for me to earn fees by linking to Amazon.com and affiliated sites.

If your carpet spot cleaner smells bad the moment you turn it on—or leaves a musty odor behind—it’s almost always a storage problem, not a cleaning problem. Moisture trapped in tanks, hoses, or nozzles turns into mold and bacteria fast. Learn how to store your carpet spot cleaner properly.

Quick Verdict:
To avoid mold and smells, store your carpet spot cleaner completely dry, with empty tanks, flushed hoses, open airflow, and loose hose storage—in a dry, temperature-stable space. Five minutes of prep after cleaning prevents months of odor and suction loss.

Why this matters:
A poorly stored cleaner doesn’t just smell—it re-deposits bacteria into carpets, weakens suction, and shortens the machine’s life. Proper storage keeps performance strong and your home fresh.

Product	Cleaning Power	Portability	Cordless	Best Use Case	Tank Size
Shark StainForce	Good	Excellent	Yes	Quick spills, pets, cars	Small
Shark StainStriker	Excellent	Good	No	Deep stains, carpets	Medium
BISSELL Little Green	Very Good	Good	No	Everyday stains, upholstery	Medium
Hoover CleanSlate Pro	Excellent	Fair	No	Large stains, carpets	Large
BISSELL Little Green Mini	Good	Excellent	No	Light stains, tiny spaces	Small

1. What Causes Mold & Smells in Stored Spot Cleaners

Understanding the “why” makes the fix obvious.

A. Trapped Moisture

Any water left in:

Dirty or clean tanks
Hoses
Spray lines
Nozzles

…creates the perfect environment for bacteria and mold.

Shark StainForce is the best cordless option for fast, everyday cleanups.
Shark StainStriker delivers the deepest cleaning power for tough carpet stains.
Hoover CleanSlate Pro is the best for large spills and high-traffic homes.
BISSELL Little Green remains the best all-around value.
BISSELL Little Green Mini is the best tiny-but-mighty option for small spaces.

B. Detergent Residue

Soap left inside hoses and valves:

Feeds bacteria
Hardens over time
Restricts airflow

Residue is a common reason machines smell even after “rinsing.”

C. Sealed Storage

Closing caps, coiling hoses tightly, or storing in airtight spaces locks humidity inside.

D. Bad Storage Locations

Garages, basements, or closets with:

High humidity
Freezing temps
Poor airflow

…accelerate mold growth and component damage.

2. Step-by-Step: How to Store a Spot Cleaner the Right Way

Step 1 — Empty Tanks Immediately

Dump dirty water
Empty any remaining clean solution

Never store liquid inside—ever.

Step 2 — Rinse Tanks Until Clear

Use warm water
Swirl and pour out
Repeat until there’s no scent or suds

Pay attention to seams and corners.

Product	Cleaning Power	Portability	Cordless	Best Use Case	Tank Size
Shark StainForce	Good	Excellent	Yes	Quick spills, pets, cars	Small
Shark StainStriker	Excellent	Good	No	Deep stains, carpets	Medium
BISSELL Little Green	Very Good	Good	No	Everyday stains, upholstery	Medium
Hoover CleanSlate Pro	Excellent	Fair	No	Large stains, carpets	Large
BISSELL Little Green Mini	Good	Excellent	No	Light stains, tiny spaces	Small

Step 3 — Flush the Hose & Spray Line

This is the most skipped—and most important—step.

How to flush:

Fill the clean tank with plain water only
Spray through the hose for 15–30 seconds
Run suction until the hose looks clear

This removes soap residue that causes smells and clogs.

This extraction-first approach—moving moisture out rather than sealing it in—is the same reason airflow matters so much in floor care, something VacuumsPal emphasizes often (including in deep-dive performance guides like Tineco S9 vs S5).

Step 4 — Dry Everything Completely

Before storage:

Leave tanks open
Hang or drape the hose loosely
Let nozzles and brushes air-dry

Do not reattach caps or coil hoses tightly while damp.

Step 5 — Store With Airflow

Ideal setup:

Tanks off or caps open
Hose loosely looped (not kinked)
Unit upright, not sealed in plastic

Airflow prevents humidity buildup.

3. Where (and Where NOT) to Store Your Spot Cleaner

Best Storage Locations

Indoor utility closet
Laundry room (if ventilated)
Climate-controlled storage room

These spaces keep temps stable and humidity low.

Avoid These Areas

❌ Damp basements
❌ Freezing garages
❌ Attics with heat swings
❌ Sealed bins or plastic bags

Freezing damages pumps and seals; heat degrades plastics.

Hose Storage Tip

Coil loosely in large loops
Avoid tight wraps around the unit
Never pinch or kink

Restricted hoses reduce suction over time.

Proper Spot Cleaner Storage Checklist

How to Store a Carpet Spot Cleaner

Task	Do This	Why It Matters
Empty tanks	Immediately after use	Prevents mold growth
Rinse tanks	Until water is clear	Removes odor-causing residue
Flush hose	Every use	Stops soap buildup
Air-dry parts	Tanks open, hose loose	Prevents trapped moisture
Store location	Dry, climate-stable	Protects components
Hose position	Loose coils	Maintains airflow

4. Common Storage Mistakes That Cause Odor

Avoid these and you avoid 90% of issues:

❌ Storing with water inside
❌ Closing tank caps while damp
❌ Coiling wet hoses tightly
❌ Using plastic bags or bins
❌ Storing in freezing temps
❌ Ignoring faint smells (they worsen)

If it smells when you store it, it will smell worse later.

FAQs – How to Store Your Carpet Spot Cleaner Properly

Why does my carpet cleaner smell after sitting unused?

Because moisture or detergent residue was trapped inside during storage.

Can mold grow inside a spot cleaner?

Yes—especially in hoses and tanks if stored damp.

Should I leave the tank cap open during storage?

Yes. Open tanks allow moisture to evaporate.

Is it okay to store a spot cleaner in the garage?

Only if it’s dry and doesn’t freeze. Climate-controlled storage is best.

How do I fix a smelly cleaner before use?

Rinse tanks, flush hoses with clean water, and air-dry fully before cleaning carpets.

How to Store Your Carpet Spot Cleaner Properly (Avoid Mold & Smells)