Your bathroom is costing you: slash damp by 70% with two cupboard staples you already own

Condensation, musty corners and rising bills keep creeping back. A decades-old fix is circulating again, and homeowners are listening.

Across the country, people battling bathroom steam are turning to a pared-back routine passed down through families. It leans on two cheap staples, takes half an hour, and promises a surprising dent in damp and energy waste.

Why a spotless extractor changes the game

Bathroom extractors fill with lint, soap film and fine dust. Airflow drops. Moisture lingers. Odours take hold. A sluggish fan quietly inflates heating costs because wet rooms take longer to warm and dry.

Clean fans shift more air, dry walls faster and can trim electricity use by up to 25% when the motor works less hard.

Engineers say a light, regular clean prevents the motor from straining and restores the designed air movement. That alone cuts the time your fan needs to run after a shower. Less run-time, less power, less residual damp.

The two-ingredient method everyone is talking about

What you need

• White vinegar: 250 ml
• Bicarbonate of soda: 30 g
• Warm water: 500 ml
• Old toothbrush for tight corners
• Three microfibre cloths
• Optional swap: 125 ml fresh lemon juice in place of vinegar

Step-by-step in 30 minutes

• Kill the power at the consumer unit. Remove the grille carefully.
• Mix vinegar with warm water in a bowl. Immerse the grille for 15 minutes only.
• Dust the fan blades. Sprinkle bicarbonate over the surfaces. Agitate gently with the toothbrush.
• Rinse parts under clean water. Dry thoroughly with microfibre cloths.
• Allow every piece to air dry fully. Refit the grille. Restore power.

Never mix vinegar with bleach or chlorine cleaners. Keep liquids away from the motor housing and live electrics.

Set a reminder to repeat this every two months. People who schedule it find the fan stays quiet, the room dries faster, and the mirror clears in minutes rather than hours.

Does it really cut humidity by 70%?

Home trials shared with our newsroom show big swings. Households using a cheap hygrometer recorded peak bathroom humidity after showers dropping from the high eighties to the mid-sixties once the fan and grille were cleaned. In small bathrooms with weak airflow, reductions of around 70% in peak readings were reported compared with readings taken before cleaning.

Why so much movement? Two reasons. First, grime on blades and grilles disrupts aerodynamics and throttles flow. Second, a clogged grille behaves like a filter. It traps moisture-laden air at the ceiling. Remove that restriction and the fan does what it was designed to do.

Why vinegar and bicarbonate work

White vinegar cuts soap scum and light limescale without harsh solvents. Bicarbonate adds gentle abrasion. Together they lift the film that coats plastic grilles and fan blades. Microfibre traps the loosened residue without scratching. The method is simple, cheap and repeatable.

Small habits that stack up to big gains

• Run the fan for 20 minutes after each bath or shower. A basic plug-in timer helps if there’s no built‑in overrun.
• Leave the door slightly ajar to improve make‑up air. A starved fan cannot pull moist air effectively.
• Crack a window during and after hot water use when weather allows.
• Keep shower curtains and bath mats spread out to dry quickly.
• Use a hygrometer. Aim for 40–60% relative humidity indoors.

Air in, air out: the fan can only exhaust what the room can replace. A closed door can undo the best extractor.

When you should go further

Upgrade checks

If your fan predates current building standards or feels underpowered, consider a higher‑capacity, low‑noise unit with a humidity sensor. Look for models rated 15–30 litres per second for small bathrooms and more for larger spaces.

Tackle sources of moisture

Water finds the weak spots. Check seals around baths, sinks and windows. Repair drips. Insulate cold pipes to reduce condensation. If your bathroom has no external vent, speak to a professional about compliant ducting to the outside rather than the loft.

Health flags

Black spotting on grout, persistent odours or wheeziness after showers point to a bigger damp problem. Seek advice, especially if anyone in the home has asthma or allergies. A portable dehumidifier can help while you address root causes.

Risks, caveats and surfaces to avoid

• Do not soak metal parts for longer than 15 minutes; acidic solutions can pit aluminium and steel.
• Avoid vinegar on natural stone, marble or cement‑based surfaces near the fan.
• Keep liquids away from the motor and wiring. Never submerge the fan assembly.
• Wear gloves if you have sensitive skin. Ventilate while you clean.
• Store bicarbonate and vinegar out of children’s reach. Label spray bottles clearly.

What this means for your bills

A clean fan shifts moisture out faster, so you can run it for fewer minutes and heat a drier room more efficiently. Families sharing utility data with us saw bathroom fan run‑times fall by a third after adopting a bi‑monthly clean. Over a year, that means fewer kilowatt‑hours and slower mould regrowth, which also cuts spending on harsh cleaners.

The ingredients cost pennies per session. A £6 hygrometer and a recurring calendar reminder turn it into a routine rather than a rescue mission.

A 30‑minute template you can reuse around the home

The same approach helps in kitchens and cloakrooms. Grease and steam clog cooker hood meshes; a vinegar soak restores them. Trickle vents on windows collect dust; a soft brush brings back air movement. Small clearances, big differences. Treat these vents and fans as you would a filter, not a fixture.

If you rent, note your cleaning dates and any faults you spot, such as noisy bearings or weak extraction. Share them with your landlord early. Good records support timely repairs and healthier rooms.