Blood stains can look alarming, but they are often fully removable if you act quickly and follow one critical rule: never use warm or hot water. Heat causes the proteins in blood to coagulate and bond permanently to carpet fibres. Cold water is essential at every step.
Why Cold Water Is Non-Negotiable
Blood is a protein-based stain. Proteins denature and set when exposed to heat, binding tightly to fibres in a way that is very difficult to reverse. This is why hot water extraction, which works well for many stains, can actually make a blood stain permanent if applied before the stain is fully removed.
Always use cold water, cold cleaning solutions, and cold rinse water throughout the entire cleaning process. This rule applies to fresh and dried blood alike.
Never use warm or hot water on a blood stain. Heat sets protein stains permanently. Use cold water at every stage, including when rinsing.
Step-by-Step: Fresh Blood Stain
Blot the fresh blood with a clean dry cloth. Press firmly and work from the outside edge inward. Avoid rubbing. Blot until you've removed as much blood as possible, changing to a fresh area of cloth each time.
Apply cold water sparingly and blot again. Then mix one tablespoon of dish soap with two cups of cold water and apply the solution to the stain. Blot, rinse with cold water, and repeat until the stain is cleared. For stubborn spots, a small amount of hydrogen peroxide (3%) can help lift the stain from lighter-coloured carpet. Always test in a hidden area first.
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Book a CleaningRemoving Dried Blood from Carpet
Dried blood is more difficult but still often treatable. Start by gently scraping up any dried surface material with the edge of a spoon. Then apply cold water to re-hydrate the stain and begin blotting. Allow the water to sit on the stain for a minute before blotting, as this softens the dried proteins.
An enzymatic cleaner designed for protein stains can be very effective on dried blood. These products break down the protein structure. Apply according to directions, allow the dwell time specified, and blot clean.
Enzymatic cleaners, the same type used for pet urine, work well on dried blood because blood is also protein-based. Look for products labelled for protein stains.
When to Call a Professional
Large blood stains, stains that have soaked into the carpet backing, or stains that have set from previous hot water treatment may require professional attention. A professional cleaner can use specialized protein-dissolving solutions and cold water extraction to address stains that DIY methods haven't fully resolved.
After the Stain Is Removed
Once you've cleared the stain, blot the area dry with clean towels and allow the carpet to air dry completely. Place a fan nearby to speed up drying if needed. Avoid walking heavily on the area until it is fully dry, as wet carpet fibres are more susceptible to re-soiling.
If you're concerned about complete sanitation of the area, particularly for a larger stain, professional steam cleaning with appropriate sanitizing agents is the most thorough option.
Carpet Hero's cleaning process can include sanitizing treatments for areas that need thorough cleaning beyond stain removal alone.