For weeks the sink has taken longer and longer to empty and now, just when visitors are coming, it's finally stopped. Typical, eh?

I'll bet you looked disbelievingly at a sink full of lukewarm, greasy water and then you logged on to bhg.com.au muttering, 'Help!'

There are three ways to attack the problem:

Chemicals
There are chemical to eat away at some of the things which may be blocking the line. Read the instructions carefully before you use the product. Chemicals are usually dangerous.

Their success varies depending on their quality, the type of chemical used, what is causing the problem, how early you attack it and, most importantly, how long you can afford to wait, assuming the sink is blocked. Often the chemicals must be left overnight.

For a quicker reaction in your sink you may have to buy or borrow a plunger (or a sink pump).

Plunger
The idea of a plunger, which is like a huge suction cup, is to create a pressure which may dislodge the object that is blocking your sink.

By placing the plunger over the waste hole and vigorously pumping it up and down you create a force which, if you're lucky and the blockage is minor, may send the tea leaves or food matter on their way.

The more efficient and more expensive sink pump gives greater pressure.

Removing the S-Bend
If, however, after much effort, the plunger doesn't work, then your last course of action is to disconnect the S-bend under the sink and manually clear the blockage.

The S-bend is a remarkably simple but effective way of sealing off bad odours which might come back up the plumbing pipes.

You'll need
Bucket or basin to catch the sink water.
Large pair of multigrips or wrench - if the large plastic nuts are too tight to move by hand.

Here's how
1. Clear the items from around the under-sink plumbing.

2. Place the bucket or basin in position.

3. Begin to unscrew the nuts on either side of the bend. (If it's an old metal type there may be a small eye on the bottom of the bend which can be unscrewed with a spanner. The blockage can then be cleared with a small piece of wire or a bottle brush).

4. Remove the bend, clean out the blockage, then screw it tightly back in place. Most plastic fittings are self-sealing. Metal sometimes needs to be caulked with Vaseline or thread tape.

5. Run some water and check the joints for leaks while saying a few prayers. If the water flows away quickly you've solved the problem. Clever you!

If it doesn't, then there is obviously a blockage further down the line which could be caused by such ominous things as tree roots, a blocked grease trap, etc. Ring your favourite plumber and leave a 'Help!' message on the answering machine.

Source: Better Homes and Gardens Home Repairs and Maintenance (Murdoch Books)