The timer does not run-on at all
Ensure the fan has been wired in accordance with the fitting/wiring instructions. Timer fans require a permanent live and neutral and a switch live to operate correctly.
The timer does not time out and so the fan runs on continuously
My fan is controlled from the light switch
My lighting is low voltage or low energy and has its own transformer
Ensure there is both a permanent live and switch live on the fan or transformer controller (where applicable) and that they have been connected to correct way round. See product fitting/wiring for full relevant wiring details.
Some types of low voltage and low energy lighting (mainly older types) can create a high voltage surge at the point the light is switched and this can interfer with and in some cases damage timers in fans. If your timer fan has failed due to lighting type you will likely need to replace it. If placing on the same lighting circuit, your electricial should protect the fan with a supression device such as a Varistor of type relevant to the lighting type.
My light does not have a transformer or is a tungsten filament light bulb
Ensure there is both a permanent live and switch live on the fan or transformer controller (where applicable) and that they have been connected to correct way round. See product fitting/wiring for full relevant wiring details.
My fan is controlled by a switch other than a light switch
Ensure there is both a permanent live and switch live on the fan or transformer controller (where applicable) and that they have been connected to correct way round. See product fitting/wiring for full relevant wiring details.
Can I adjust the run-on timer
Run-on timers can usually be adjusted between approximately 3 - 30 mins (this range varies depending on the fan). See product fitting/wiring for guidance.