Sewer pulsation is usually caused by an air pressure imbalance in the sewer system. When water in the sewer drains down, it needs air to replace it. If air cannot flow normally through the vent pipes, it will try to enter the drain pipe by other routes, such as the sink or toilet seat. This causes the familiar bubbling sound. The problem can be caused by a blocked drain, inadequate ventilation or a partial blockage that obstructs both water and air flow.
What makes the drain pulsate?
Bubbling sound occurs when the air pressure in the drainage system is not balanced. In a functioning sewer system, water flows down the pipes, and the ventilation pipes bring replacement air into the system from above. When this balance is upset, the air seeks alternative routes, causing the audible pulsation.
The most common cause of pulsation is a partial blockage in a sewer pipe. When a blockage narrows the diameter of the pipe, water flows more slowly and creates a vacuum behind it. This vacuum space sucks air from the nearest drain hole, which is heard as a pulsation. Blockages are often caused by grease, hair, soap residue and other household waste that collects more material on its surface.
Another major cause is inadequate or blocked air conditioning. The ventilation pipes of the drainage system extend to the roof of the house and their function is to balance the air pressure in the drainage system. If these pipes become clogged with leaves, bird nests or, in winter, ice, the air cannot flow normally. The system then starts to draw air from other openings, causing pulsation.
Sometimes, pulsation can also be caused by design flaws or outdated plumbing. Pipes installed with too small an angle of inclination or incorrectly sized ventilation can cause problems, even if there is no actual blockage.
Is a bubbling drain a sign of a serious problem?
A bubbling drain is not always a serious problem, but it is a sign that the system is not working optimally. A slight pulsation may indicate the onset of a small blockage or a temporary ventilation problem, which can often be fixed with simple measures. More serious problems, however, require professional assessment and intervention.
Worrying signs that require a quick response include multiple drains pulsating at the same time, water rising back into the basins or floor drains, and an unpleasant smell. These can indicate a serious blockage in the main sewer line, which can lead to water damage if not repaired in time.
If the pulsation only occurs in one drain and is sporadic, it is probably a local problem. In this case, you can try simple cleaning methods before calling a professional. If the pulsation is persistent or getting worse, don't wait too long. It's best to act quickly to fix a blockage at home, as a prolonged problem can lead to more extensive damage and more expensive repairs.
A particularly serious situation is one where the water does not flow at all or flows very slowly in addition to pulsating. This indicates that the blockage is already significant and requires immediate intervention. Water damage can occur quickly, and the constant flow of water can damage the structure of the house.
How do you fix a sewer backflow?
In the simplest cases, you can fix the bulge yourself with basic tools. Start by trying hot water and dishwashing liquid, which can dissolve grease-based blockages. Slowly pour boiling water down the drain and let it sit for a while. This often helps in mild cases, especially in kitchen drains.
A sewer suction valve, or pump, is an effective tool for partial blockages. Fill the basin with a little water, place the pump tightly over the drain and pump vigorously up and down. This creates pressure surges that can unclog the blockages. Be sure to plug the overflow hole before pumping so that pressure is effectively applied to the blockage.
A drain cleaner can help, but use it with caution. Strong chemicals can damage old pipes and are harmful to the environment. Biological cleaners are a safer alternative, but their effect is slower. If you decide to use a chemical cleaner, follow the manufacturer's instructions carefully and ensure good ventilation.
Mechanical cleaning with a sewage reel is an effective method for deeper blockages. You can hire a sewage reel from hardware stores, but it does require some experience. The coil is inserted into the drain and rotated, breaking up or pulling out the blockage-causing material.
If these methods don't help or you suspect problems with your air conditioning pipes, it's time to call a professional. We have specialised equipment, such as imaging equipment and powerful opening machines, to locate and remove even the most difficult blockages. Our professionals can also assess the condition of your air conditioning system and make the necessary repairs quickly and safely.
Can you fix a bubbling drain yourself or do you need a professional?
Simple pulsation problems can often be fixed by yourself if you have basic tools and some handyman skills. Mild blockages in individual drains that respond to hot water treatment or pump operation are well suited to independent repair. This saves money and solves the problem quickly.
However, there are several situations in which you should contact a professional. If several drains are pulsating at the same time, the problem is likely to be in the main sewer line or the air conditioning system. These require specialised skills and equipment not usually available in households. A professional should always be consulted for advice on a pipe blockage in the home that affects the drainage of the whole house.
Repeated pulsation problems, even if they seem to be temporarily resolved, indicate a deeper problem. In this case, independent attempts to fix the problem can only delay finding the right solution and make the situation worse. A professional can make a thorough diagnosis and fix the problem permanently.
If you suspect problems with the air ducts, don't try to fix them yourself. Climbing on the roof is dangerous, and improper handling of the ventilation system can make the problem worse. We have safe access to the roof and can professionally assess the condition of your air ducts.
The threat of water damage is always a reason to call a professional immediately. If water is threatening to come back up from a drain or floor drain, don't wait. Give us a call and our on-call plumber will arrive quickly, in as little as 15 minutes. A quick response prevents costly water damage and structural damage. We offer round-the-clock service precisely because drainage problems don't follow office hours, and we want to be there for you whenever you need us.
