It can be worrying if you have ever seen water dripping from the overflow pipe. You may be wondering what is wrong and whether or not you need to call a plumber.
In most cases, it’s usually not a big deal. However, it is usually a sign that there is a problem that needs to be fixed. Keep reading to learn more about why my overflow pipe is dripping and what you can do to prevent it.
What is an overflow pipe?
An overflow pipe is a pipe that safely drains excess water to prevent water from overflowing inside the home.
These pipes can be found in all kinds objects and structures used to hold or carry water, such as tanks. In addition to preventing overflow, overflow pipes also help reduce the likelihood of a tank or channel holding too much water and collapsing due to pressure.
Overflow pipes are a form of safety measure and as such generally only let water through at all times. Because water only passes when the reservoirs reach the level of the overflow pipe, most overflow pipes discharge only drops of water, rather than discharging water in large volumes.
These cases indicate something is wrong with the line and should be addressed. For example, there could be leaks along the line or other problems causing water to flow into the overflow pipe. Below are possible reasons why water is dripping from an overflow pipe.
WC cisterns
Toilet cisterns are present in almost all households. They have an overflow pipe to prevent the toilet from overflowing. In a properly functioning toilet, the water should be about an inch below the overflow pipe. To stop the water from reaching overflow pipe, toilet cisterns have a float valve.
1. The water pressure is too high
The water level can rise drastically if the water pressure is too high. This rise in water can cause water to reach the overflow pipe. To prevent overflow, the water pressure must be regulated.
If the water pressure is too high, it can cause problems throughout the house. Pipes can clog or burst, appliances can be damaged, and you may even see your water bill rise.
Fortunately, there are some simple steps you can take to reduce water pressure in your home. First, check to see if there is a main shutoff valve. If so, turn it clockwise until the water pressure drops.
Next, check all light fixtures in your home and see if they have individual shut-off valves. If so, turn these valves clockwise as well.
Finally, if you have a pressure reducing valve (PRV), adjust it until the desired water pressure is reached. By following these steps, you can easily reduce the water pressure in your home and avoid any potential problems, including overflow.
2. The float valve is set too high
The float valve can be adjusted to regulate the amount of water filling the tank. In most cases, float valve is set so that the tank fills about an inch below the overflow pipe.
However, setting the float valve incorrectly causes the tank to be filled above what is recommended, causing water to enter the overflow pipe. In these cases, the float valve can be adjusted and returned to normal to prevent overflow.
3. Float valve not working as intended
As the name suggests, the float valve uses a float to regulate the flow of water. However, preventing the float from moving can prevent the float valve from working properly. In most cases, the chain becomes twisted, locking the float in place.
This prevents the valve from closing, resulting in the tank overflowing. Other forms of damage may occur. In any case, the float valve must be repaired or replaced to stop the toilet tank from overflowing.
Cold water supply and expansion tank
Cold water supply and expansion tanks store water for the heating system. These tanks are usually fed through a ball valve. The tank can be made of different materials, such as plastic or metal.
The water in the tank passes through the heating systems and supplies water wherever it is needed, such as through the taps. These tanks also have overflow lines to prevent overflow, and below are some reasons why the cold water supply and expansion tank overflow line is letting water out.
1. The water supply has not been interrupted
A ball valve is usually used to regulate the flow of water into the tank. In most cases, the valve must be opened and closed manually to regulate the water flow.
However, there are cases where the valve does not work properly. For example, a faulty valve may still allow water to flow into the tank even though it is closed.
Some tanks use float valves to automatically regulate the flow of water in the tank without requiring much human intervention. However, just like the ball valve, faulty float valves also fail to cut off the water supply, increasing the volume of water inside the tank.
This leads to overflow if the water in the tank is not immediately fed to the heating systems. As such, valves must be well maintained and repaired or replaced whenever damage is observed.
2. The water is returned to the tank
If the supply valves are working fine, but water is still coming out of the overflow pipe, then water is probably backing up into the tank. This usually happens when a faulty mixture is used because hot and cold water have different pressures.
What happens is that the pressure difference pushes the water back into the tank, which can cause the tank to overfill. There are other possible causes, so it’s best to call a plumber to repair the system and prevent water from re-entering the tank.
Copper cylinder
A copper cylinder is a vessel used for heating and storing water. It is connected to the cold water supply and the expansion tank and gives the water room to expand when heated.
Copper cylinders are made of copper due to the thermal properties of the material. Below are possible damages that the copper cylinder has suffered, causing water to leak into the overflow pipe.
1. The temperature or pressure is too high
Copper is a good conductor of heat, allowing it to transfer heat more efficiently to the water inside. However, when the temperature becomes too high, the pressure inside the cylinder also increases.
This causes vapor to try to escape from the cylinder, causing a leak. The temperature must not be too high to prevent the cylinder from overheating, thus effectively lowering the resulting pressure.
2. Perforations inside the copper cylinder
Copper cylinders don’t last forever. In fact, copper is quite susceptible to wear. Punctures along the cylinder or pipes connected to the cylinder can cause leaks. The heating coil inside the copper cylinder is also susceptible to wear and tear and may have punctures.
Water can drain from these perforations, resulting in tank overflow. In these cases, the only solution is to replace the copper cylinder.
Overflow pipe for sink and bathroom
Have you ever noticed the small hole behind the sink, usually located under the faucet? That hole can often lead to the overflow pipe and is used to stop water from overflowing from the sink. The same hole can be found in bathrooms to prevent water from overflowing when the faucet continues to run.
Problems with these devices are easy to spot and can be easily fixed. For example, a clogged drain can be cleared to allow water to drain better. A faulty faucet can also be repaired or replaced to stop the flow of water into the tub or sink, thus preventing an overflow.
Boiler overflow pipe
Boilers do not necessarily have overflow pipes to prevent water from overflowing. In contrast, boilers, similar to pressure cookers, have pressure relief valves. As the water boils, the pressure inside the container increases.
A pressure relief valve is attached to prevent the boiler from bursting due to pressure. The pressure relief valve releases steam whenever boiler pressure becomes too high. The pressure can be adjusted by allowing steam to escape from the boiler.
In cases where the pressure relief valve releases steam without stopping, there is usually a problem. One such problem is that the boiler has too much pressure inside, possibly due to a faulty expansion valve.
It can also result from a faulty pressure valve improper pressure release, leading to inadequate heating of the water. In any case, the boiler should be assessed and repaired by an engineer before it becomes a bigger problem.
Final thoughts
In general, a leaking overflow pipe can come from a variety of reasons, from a faulty toilet cistern to a faulty tank supply valve. Unfortunately, it is quite difficult to identify the source of the leaks because the parts are connected.
In order to be able to determine the real cause, each component of the line must be checked. Therefore, professional help is always recommended, especially when the problems involve the heating system.
Sometimes, however, the cause is obvious. For example, if the overflow pipe is dripping every time you flush the toilet, then it’s a great idea to check the tank. We hope we’ve given you all the information you need to stop your overflow pipe from dripping.