What Causes Backflow in Plumbing? | IT Landes
Plumbing backflow in Mountgomery county, Pennsylvania

Backflow happens when the water comes out of one drainage pipe and goes back into the other. The hot water that usually goes out through a kitchen sink or bathtub drains back down and enters the cold water in a cold-water supply pipe. If you have an indoor sprinkler system, backflow can happen if someone turns on a faucet or starts using an air conditioner connected to your main line for cooling.

Backflow is a problem if it is not spotted in time. The pressure of the water entering the hot-water line can burst, causing water to spill all over your basement or washing machine. It can also cause the temperature of the water to rise, which can be dangerous if anyone flushes a toilet or takes a bath. Here’s what you need to know about backflow, its causes, and how you can prevent it.

Types of Backflow in Plumbing

There are two main types of backflow: backpressure and back-siphonage. Backpressure occurs when too much pressure comes from the main line or an improperly placed pump. It results from internal backflow, which happens when water flows back into the household system through a plumbing fixture. The most common cause of internal backflow is when a hose bib, faucet, or other device attached to the system is turned on without first being opened.

Backpressure backflow can also result from external backflow. This can happen if someone uses a toilet brush or toothbrush to clean the bowl instead of using the toilet’s built-in brush or if the water used to wash a dish or stovetop is disposed of down the drain. Since the water is not disposed of properly, it re-enters the system through the sink or bathtub drain and causes backflow. External backflow is more common in rural areas that do not have separate storm-drainage systems.

Back-siphonage is a backflow problem when water from a separate drainage system enters the household plumbing. It commonly happens in rainwater systems. It results from secondary backflow, which occurs when water comes back through the wastewater treatment process and into your drain. It can occur if your home’s plumbing is connected to a water recycling system that goes directly to the toilet or if you use a laundry machine that recycles for its greywater source. Minor blockages can also cause sewerage pipe damage. These blockages can occur in the underground pipe or the utility hole.

What Leads to Backflow in Plumbing?

The following are the main events that can cause backflow to happen:

1. A Broken Water Main

If you have a broken main, the system may not be able to deliver enough water to keep up with demand. The system may also leak, which can cause leaks in your house or even sewage to pour into your basement. You may also hear loud squeaking or popping sounds when you rinse dishes in the kitchen sink, and there are no drains clogged with food and other debris.

2. Prolonged Power Breakdown

An extended power breakdown is another major backflow event to watch out for because it can lead to the growth of bacteria in your system. Water in a storage tank can stagnate, which allows bacteria to grow. If this happens in the hot water tank, it can cause an eruption of scalding hot water when you try to take a shower or bath. It is also important to note that hot water systems have small electric pumps that circulate water through the pipes.

3. Plumbing Overhauling

A plumbing overhauling can lead to backflow because the water is not draining out of the system. It is especially true if you have an older home that has been fitted with new pipes and fittings that are different than the previous pipes.

4. In-house Pressure Difference

If there is water from the main line in your home and you cannot turn on a sink or bathtub faucet without causing a backflow, then there is an in-house pressure difference. Note that this is different from the pressure caused by a broken main, which is the amount of pressure from both the main line and the tank.

Potential Sites of Backflow

Below are some of the common sites that can lead to backflow.

1. Bathroom Faucet

If a bathroom faucet is leaking, it may cause water to flow back into the cold water line. The bathtub and sink water in your toilet may become contaminated. To fix the problem, you should either replace or repair the faucet. You should also inspect the pipes for signs of corrosion and fix any leaks found.

2. Clogged Drain or Sewer

The blocked water can go back into the plumbing if you have a clogged drain. It is more common in older homes that use pipe traps. If you want to fix this, you can use a drain snake or a chemical drain cleaner. Note that a clog in your sewer line can also cause backflow problems. If you suspect this is the case, call for professional assistance to fix it.

3. Outdated and Damaged Fittings

If an outdated fitting or damaged pipe is in your home, it may not be able to remove all of the water from the plumbing system. If this happens, you might end up back floating in your toilet or shower which is dangerous, so it’s essential to schedule an inspection when you notice this happening.

How to Fix Backflow in Plumbing?

There are two main ways that you can deal with a backflow problem: air gaps and backflow prevention devices. You can install air gaps on sinks, tubs, and toilets. They are easy to install and require no additional equipment other than the pipe. In a plumbing system, potable water and wastewater are intended to flow in opposite directions to prevent contamination. The air gap is a one-way valve, meaning water can only flow from the potable side to the waste side of the fixture. It also prevents gases from flowing from the waste to the potable water side of a plumbing fixture. Air gaps are easy to maintain and do not require annual inspections, making them very cost-efficient.

You can also utilize a backflow prevention device, which is used to prevent the contamination of potable water sources in your plumbing system. Check valves and vacuum breakers are the most common types of these devices. Backflow prevention devices control the direction of water and are usually installed where plumbing fixtures connect to the main drain line. They should not be confused with back-siphonage preventers used for wastewater applications. There are different types of backflow prevention devices, including:

  • Pressure Vacuum Breaker Assembly
  • Reduced Pressure Backflow Prevention Assembly
  • Spill-Resistance Pressure Vacuum Breaker Assembly
  • Double Check Valve Assembly

Our professionals at IT Landes in Harleysville, PA, can help you choose the right one for your needs.

Contact the Professionals

An important thing to note is that backflow does not only apply to plumbing systems. It applies to many other industries, such as water and air flow systems. At IT Landes, we provide home, commercial, and industrial plumbing and HVAC services, including design, special projects, maintenance work, installations, and repairs for clients in Montgomery and Bucks Counties. Contact us today to schedule an appointment with our friendly and experienced technicians.

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