Households say a quick clean of the bathroom extractor using white vinegar and bicarbonate of soda restores airflow, tames fog, and cuts musty odours. The promise sounds bold because it is: faster drying, fewer mould spots, and a smaller energy tab when the heating kicks in.
Why this old trick is back
Autumn brings condensation, blackened sealant, and towels that never seem to dry. Small rooms with weak extractors get the worst of it. A grimy grille and dust‑clogged fan blades slow the draw of moist air. The result is stale smells, peeling paint, and higher heating demand as surfaces stay wet for longer.
People are turning to two cheap staples—white vinegar and bicarbonate of soda—to strip grease and dust from the fan and grille. Clean parts move more air. More air means quicker moisture removal after a shower. Less lingering moisture means less mould risk and less heat lost to drying out the space later.
Up to 70% lower post‑shower humidity and around 25% lower electricity use for ventilation have been reported in household trials.
What the method actually does
White vinegar cuts soap film and odours on the grille without harsh fumes. Bicarbonate of soda loosens stubborn dust on the blades. The fan runs at its intended speed when clean, so it clears steam faster. You do not need fancy tools, just care, patience, and dry hands.
Step‑by‑step in under 30 minutes
- Turn off power at the consumer unit. Remove the extractor grille carefully.
- Mix 250 ml white vinegar with 500 ml warm water. Soak the grille for 15 minutes, then wipe clean.
- Sprinkle 30 g bicarbonate of soda on the fan blades. Brush gently with an old toothbrush until the dust lifts.
- Rinse parts with clean water. Dry everything thoroughly with microfibre cloths so no moisture reaches the motor.
- Refit the grille only when every surface feels bone dry. Restore power and test.
If you are out of vinegar, a small splash of lemon juice works on the grille. Avoid mixing vinegar and bicarbonate in a paste on the fan. They neutralise each other and can fizz where you do not want moisture.
A clean fan is a quieter fan. Air moves freely, mirrors clear sooner, and condensation retreats from paintwork and grout.
How to check the results
Use a small digital hygrometer. Log bathroom relative humidity after a hot shower with the door closed. Run your fan on, then note how long it takes to fall below 60% RH. Repeat the test after cleaning. Most homes aim for 40–60% RH once the room settles.
Run the extractor for about 20 minutes after bathing. Set a simple timer so you do not forget. Mark your calendar to clean the fan every two months. Choose a routine, such as the first Sunday of each even month, to keep it consistent.
Will it really save you money?
The electricity savings from the fan alone are small, but real. The bigger win often comes from heat you no longer waste drying a sodden room.
| Scenario | Fan electricity per month | Indicative heating impact | Headline outcome |
|---|---|---|---|
| Dirty fan, 50 min/day to clear steam | ~0.62 kWh (about £0.17 at £0.28/kWh) | Surfaces stay wet longer; more heat lost to evaporation | Lingering damp, higher mould risk |
| Clean fan, 40 min/day to clear steam | ~0.50 kWh (about £0.14) | Faster drying; less latent heat demand on cold days | A few pence saved on the fan, plus pounds on heating |
One hot shower can release 0.5–1.5 kg of water into the air and onto surfaces. Evaporating 1 kg of water absorbs about 0.63 kWh of heat. If efficient extraction stops a chunk of that moisture spreading through your home, your boiler or heat pump works less to re‑dry rooms. On a £100 monthly gas bill, even a 1–3% reduction from better moisture control is £1–£3. The vinegar and bicarbonate cost around £2–£3 for several cleans.
Mistakes to avoid and safety checks
- Do not work live. Always cut power at the consumer unit.
- Keep liquids away from the motor housing and wiring.
- Do not soak the fan body. Only the removable grille goes in the solution.
- Dry parts completely before refitting to prevent corrosion.
- Avoid abrasive pads that can score plastic and invite grime to stick again.
- Wear gloves if you have sensitive skin. Vinegar is acidic.
Beyond the fan: small habits that compound
Crack the bathroom door open a touch once steam thins. Squeegee tiles and shower screens to dump water straight to the drain. Hang towels with space around them so air can pass. Keep window trickle vents open. These low‑effort moves shorten drying time and reduce condensation elsewhere.
For odours, cotton sachets with a handful of rice can help, but they do little to absorb heavy moisture. Silica gel or calcium chloride tubs draw far more water in very humid spaces. Swap them out as they saturate.
When to upgrade the hardware
If the fan drones or barely moves tissue paper held near the grille after cleaning, the motor may be tired or the duct blocked. Short duct runs, smooth rigid pipe, and fewer bends improve airflow. A 15‑minute overrun timer or a humidity‑sensing model keeps extraction going long enough to finish the job without you hovering by the switch.
What the numbers mean in practice
Relative humidity tells you how close air is to saturating. Warm air holds more moisture. When a cold wall meets wet air, you hit the dew point and water forms. That encourages mould and eats into your heating budget because wet surfaces feel colder and demand more heat to reach comfort.
Try a quick simulation at home. Take a baseline reading in a dry bathroom, then shower as normal. Start the fan and note RH every five minutes. After a clean, many households see the curve drop faster. If RH falls below 60% within 20 minutes rather than 40, you halve the window for condensation to creep into corners and behind furniture.
A fast, cheap routine that protects your home
Keep a small caddy ready: a bottle of white vinegar, a tub of bicarbonate of soda, an old toothbrush, and two microfibre cloths. Schedule a regular clean, log RH readings monthly, and adjust the fan overrun to hit that sub‑60% target. The kit is inexpensive, the task takes minutes, and the gains stack up through winter.
Small efficiencies add up. Drier rooms warm more evenly, towels smell fresher, and the extractor lasts longer because dust no longer drags on the motor. That is how a humble cupboard pairing turns into less mould and lower bills without touching a single chemical aerosol.
