Gurgling drains should never be ignored as they are your early warning that you are potentially about to experience blocked sewer drains.
Generally the sounds of gurgling drains will be coming from your toilet or from the bathroom floor waste drainage trap when you are using other plumbing fixtures. Very simply gurgling drains are similar to you experiencing an asthma attack because the drain is struggling to breath.
What has occurred in your underground sewer drains is that the drains are full of waste water that are blocking or partially blocking the drains vent pipe that connects from your drain and extends up above your roof.
Therefore when you use any of your plumbing because the vent is not letting the drain breath the drain creates a vacuum through a toilet pan or floor waste trap or occasionally a laundry tub in an attempt to get air. Normally only part of the water in the fixture trap is sucked out leaving the remainder of the water in the trap and it this water movement that causes the gurgling drains as air is sucked into the drain.
The interconnecting plumbing and sewer drainage system in your home is a very simple system but it must be able to breath and get air into the system through your vent pipes. Many people believe that the vent pipe is a stink pipe to remove smelly sewer odours from the sewer drain. This is partially correct but the vent pipes other job is to equalise air pressures within your sewer drains and give you a balanced system that allows waste water to flow.
Very simply whenever you flush the toilet or have a shower or turn your washing machine on the waste water immediately runs into your sewer drains. Instantly in the drain you get water and air displacement with a vacuum being created behind the flowing water that sucks air into the drain to equalise the pressure in your drain and allows the water to flow.
Gurgling drains should never ever be ignored as they seldom go away and should be investigated immediately.
By Gary Mays