Identify a Blocked Drain

Blocked Sewer Drains

There are number of reasons why a sewer drain will block, including the fixtures inside may be very slow to drain, e.g. The toilet or shower may fill with water to a level far above normal.

• Water may overflow from the gully trap outside the house. Gully traps, known as 'overflow relief gullies' or 'disconnector gullies' (see 'Overflow relief gully' picture) are installed into sewer systems as emergency points for water to overflow from in the case of a blocked drain, instead of having sewerage water overflow from the lowest fixture inside, usually the shower. These gully traps can also serve as an access point from which a plumber can clear blockages.


• A gurgling noise may be heard from fixtures or traps.


• The water seal or trap in some fixtures may become very low or even disappear. The most visible water seal in the home is the water in the toilet bowl. Low water levels and gurgling are caused by siphonage in the drain, which indicates the pipes are nearly completely blocked.

Blocked Storm water Drains

• A blocked stormwater drain is less likely to be noticed than a blocked sewer. A blockage only affects a stormwater drain when it rains, at which time we are usually inside and don't notice that the storm water drain outside is overflowing.


• In some cases blocked storm water drains will cause the roof gutters to overflow, causing roof leaks.

If you come across any of the situations mentioned above, you most likely have a blocked drain.

Don’t waste time Call O’Shea Plumbing & Blocked Drains Specialists today & have your blockage removed fast.

• Phone: 9888 2887
• Email: Email us
• Blocked Drains Inquiries