Yes

If the product has been installed in accordance with the fitting/wiring instructions and there is a supply at the fan but the shutters or shutter and fan do not work, then return to the place of purchase for a replacement.

No

Check there is a stable supply to the fan. If possible, check that there is no obstruction to the shutter mechanism and blades.

Wall Mounting
Core cut the relevant size hole, full details are in the relevant F&W

The guarantee period will vary according to the product, and is usually stated on back page of the product instructions.

However, for general guidance, go to our product guarantee page.

A common question, and the guidance below is more relevant to domestic-type installations.

Domestic Axial fans
An axial fan has a fan blade like a ship propeller. These are low-pressure fans and a general rule of thumb for these is to use no more than 1.5 metres of ducting. On a 100mm fan/ducting system, a 90 degree bend is equivalent to 1 metre, preferably rigid duct. For longer runs, a centrifugal-type fan should be considered.

Domestic Centrifugal fans
A Centrifugal fan has a fan blade like a hamster wheel. The question of duct run length becomes more difficult here. Centrifugal fans are higher pressure fans and so cope better with ducted runs or where installations are in exposed positions such as an external wall prone to strong gusty winds. To know how far a Centrifugal fan is going to push the air means knowing the overall system resistance/pressure - Anything in the path of the airflow causes a resistance - this could be ducting straight lengths, bends, filters, grilles etc..... In a domestic wet room, you need to consider a Centrifugal fan once you are over 1.5 meters of ducting, but you must still ensure that the chosen fan will achieve the required airflow for the room being ventilated with the system resistance taken into account.

You should not put more than one fan into a common duct.

Each fan should have its own duct run to the atmosphere. If you try to combine them into a common duct it will bring with it a number of problems, including an unbalanced system with positive/negative air pressures which play havoc with the fan motors and could cause motor failure. It can also cause cross-contamination issues.

Also, not to forget that incorrect installation of the fan could void the product warranty.

In residential and some commercial applications, an alternative to multiple fans into common ducts could be a Central Extract System Fan

It may be that the humidity level within the room is not high enough to trigger the fan. Where necessary, with most humidity fans you can adjust the sensitivity of the humidity sensor. See product fitting/wiring instructions for guidance. 

Where necessary, with most humidity fans you can adjust the sensitivity of the humidity sensor. See product fitting/wiring instructions for guidance. Normal ambient humidity levels on a given day can trigger a humidity fan in just the same way as humidity generated by steam from the bath/shower room or Kitchen if the humidity level rises above the set point. New build properties, as well as refurbished/redecorated properties, will go through a drying out stage during which the dampness being drawn out from walls, ceilings etc is going to affect the humidity level within the room, and a fan humidity sensor will trigger if the humidity level rises above the set-point.