Both fans covered on this page are dMEV (decentralised Mechanical Extract Ventilation) fans. They are designed to run continuously, 24 hours a day at a quiet low 'trickle' speed, automatically increasing when they detect higher humidity. Do not turn your fan off at the isolator switch for day-to-day use, as it needs to keep running to prevent damp and mould.
Greenwood CV2GIP
Smart features on this fan:
- HumidiSMART™ — automatically boosts the fan when it detects a rapid rise in humidity, such as from a shower.
- TimerSMART™ — boosts the fan when the room light is switched on, and keeps it running for a set period after the light goes off. Note: it may not trigger an overrun if the light is only on for the first 5 minutes.
The fan isn't running at all
- Find the isolator switch, which is often a pull-cord inside the room, or a separate switch on the wall outside, sometimes with a red indicator. Make sure it is switched ON.
- Check your consumer unit (fuse box) for a tripped switch labelled 'Bathroom Fans', 'Upstairs Lights', or similar. Try resetting it once. If it trips again, call an electrician.
The fan runs on trickle but doesn't boost
- HumidiSMART not boosting: Remove the front cover (see cleaning steps below) to access the control pad. Press any button to wake it, then press the button next to the humidity symbol (three water droplets) to confirm the indicator light is ON.
- TimerSMART not boosting with the light: Access the control pad as above and confirm the TimerSMART feature is enabled. Bear in mind, it won't boost if the light has only been on for a few minutes.
The fan is noisy or less effective
Dust build-up on the impeller is the most common cause. Clean the fan as follows:
- Turn the fan OFF at its isolator switch and at the consumer unit.
- Remove the front cover with an anti-clockwise twist.
- Wipe the inside of the cover and casing with a soft, damp cloth. Use a soft brush or vacuum brush attachment to gently clear dust from the fan impeller. Do not use cleaning solvents.
- Refit the cover with a clockwise twist until it locks.
- Restore power at the consumer unit first, then the isolator switch.
If the fan is clean and powered but still not working correctly, it may need a reset by a competent person or an engineer, as this involves accessing the main body of the unit.
Envirovent Infinity
Smart feature on this fan:
- Intellitrac® Humidity Tracking — rather than simply switching on and off, this fan continuously monitors the air and gradually increases speed when it detects rising humidity, then eases back to trickle once the moisture clears.
The fan isn't running at all
- Find the isolator switch, which can be a pull-cord inside the room or a switch on the wall outside, sometimes with a red indicator. Make sure it is switched ON.
- Check your consumer unit for a tripped switch labelled 'Bathroom Fan', 'Upstairs Lights', or similar. Reset it once if tripped. If it trips again immediately, leave it and call a qualified electrician.
The fan runs on trickle but doesn't boost
- Humidity sensor: The Intellitrac® sensor reacts to significant changes in humidity; a small amount of steam may not trigger a full boost. To test it properly, run a hot shower for 5–10 minutes. The fan should audibly increase speed, though the change is gradual rather than instant.
- Manual boost cord (if fitted): Pull the cord once to activate maximum speed, and again to return to automatic mode. If this works, the fan motor is fine and the issue is likely with the sensor settings.
The fan is noisy or less effective
Dust on the filter and impeller is the most common cause. This fan has a washable filter. Clean it as follows:
- Turn the fan OFF at its isolator switch and at the consumer unit.
- Remove the front cover by unscrewing the central screw (which may be under a small cap), then gently pull the cover away.
- Remove the circular foam filter from the centre. Wash it in warm soapy water, rinse thoroughly, and allow it to dry completely before refitting.
- Use a soft brush or vacuum brush attachment to clear dust from the impeller and casing. Do not use water or solvents inside the fan unit.
- Once the filter is fully dry, refit it and secure the cover with the central screw.
- Restore power at the consumer unit first, then the isolator switch. The fan will restart in trickle mode.
If the fan is clean and powered but still not working correctly, call an electrician. The internal speed and sensor settings are configured at installation and should not be adjusted without the proper knowledge.
