When fat or oil blocks up a drain pipe, you can use heat to melt the fat and unblock the pipe. Use a portable heater, or if one isn't available, a hair dryer to warm the drain pipe around the bend. This treatment will usually make the obstruction clear, and the waste should start moving again. Turn on the hot water tap for at least a minute. This will wash away all traces of fat or coagulated oil.

A plunger is almost always a good option for unclogging drains. You will usually achieve the desired results with a plunger. That is what we always wanted. Make sure you completely cover the cup of the plunger with water, and cover the overflow inlet with a piece of cloth.

After you've successfully cleared a drain, look for signs of wearing on the rings and replace them before reassembling the fittings. The seals also need to be properly positioned. If you don't do this the proper way, the pipe could spring a leak at a later date. I don't imagine anybody would want experience this.

It is usually best to work from the outside when unblocking a waste pipe manually. You will need to place a bucket under the end of the pipe before removing the obstruction.