A centralised, ducted vacuum system can be a real boon for a homeowner and is one of the most efficient ways to keep your house looking spick and span. However, sometimes you need to do a little bit of troubleshooting when it's not working as efficiently as it should. If you're not getting good suction, but the system appears to be working okay otherwise, it is likely that you may have blockage in the vacuum tubing. What can you do?

1. First, look for the obvious blockages. There may be a chunk of "debris" stuck right next to, or just inside the power unit, or immediately within the mouth of each inlet.

2. If you cannot see anything obvious, you need to determine exactly where the blockage is before you can proceed. You do this by working out the position of the inlet furthest away from the vacuum power unit that's exhibiting a problem. Your clog will be between that point and the power unit.

3. Once you have identified the position where you will be working, try connecting a portable vacuum unit to the inlet and try and reverse-suck whatever is in there.

4. Next, get a plumber's snake from your local hardware store and run this through the ducting in an attempt to hook the object.

5. Another way to try and dislodge the blockage is to plug the end by attaching the hose and then placing your hand over the open hose, while running the system. This will build up pressure. Suddenly release the pressure by taking your hand off the end, and the variation in pressure may be enough to dislodge whatever is clogged there.

6. Next, you can try using the string method. Feed the end of a small piece of string through from the motor unit to your inlet location. Then, tie a sturdier piece of string to the motor end and attach a large object to that piece of string. Then, tie another piece of string to the larger object, in order to be able to pull it backwards if necessary.

From the inlet end, pull the small string, which will in turn bring the second piece of string with the heavy object, hopefully all the way through to the end while dislodging the clog.

If all these methods fail, then you should pick up the phone and call a ducted vacuum centre such as Premier Clean in order to get a technician to help you out.