Backflow is a serious plumbing problem that is not talked about often enough. Unlike most plumbing issues in your home, this particular problem is not always accompanied by physical damage to your plumbing.
In other words, your plumbing may look perfectly fine while backflow is going on inside the system, says Century 21 Northstar experts. This is why backflow issues go on for a long time without detection. What is plumbing backflow, what are the causes, and how can you prevent it?
What is plumbing backflow?
Plumbing systems are designed to work a certain way. When the plumbing functions correctly, the water inside the pipes flows in only one direction. But sometimes problems happen, causing the water to reverse direction and creating a hazardous problem known as backflow.
Backflow introduces contaminated water into your fresh water supply. Often, this problem is not apparent because the color, taste, and smell do not change. What causes backflow, and what are the signs that backflow is happening in your plumbing system?
Causes and signs of plumbing backflow
Backflow happens because of Back Siphonage and Back Pressure.
Back Siphonage
Back siphonage is caused by sudden changes in water supply pressure. This pressure drop creates a vacuum inside the line. If the fall in water pressure is high enough, it will draw contaminated water from your drainage pipes into the freshwater lines.
Back siphonage can occur following a break in your main water line or a drop in water pressure from the municipal supply. Firefighting activities may remove too much water out of the system too fast, causing a massive drop in pressure inside the water lines.
Back Pressure
Back pressure originates from the downstream section of your plumbing. Appliances can place a demand on the water supply beyond what it can meet. Pressure imbalances from the shortfall between demand and supply can result in backflow.
The water pressure demands of boilers, water heaters, pumps, power washers, and irrigation systems may exceed the water supply. This can overload the fresh water supply line, leading to contaminated water flowing into the pipes.
What are the signs that you may have backflow issues in your plumbing system?
- If your water has a grayish, pinkish, yellowish, or brownish hue, you may have backflow problems.
- Strange odors in your home’s water supply, especially the smell of sulfur, may be due to backflow.
- The presence of small particles inside your water could be because of backflow.
- If your home has experienced or is experiencing a dip in water pressure, you need to check for backflow issues.
- If you have appliances that need high water pressure, you should have your plumbing checked for backflow.
- If there has been recent firefighting activity around your home, you may have backflow problems.
How to prevent plumbing backflow
By using one or a combination of the following methods, you can prevent backflow in your plumbing.
Air Gaps
This is an unblocked vertical space between a water supply outlet and the flood level of the receiving fixture. The physical separation between the two sides ensures no risk of contaminated water siphoning from one side into the clean water supply. Air gaps are the most basic type of backflow prevention. Air gaps already exist in some of your plumbing’s features, such as sinks and dishwashers.
Hose Bib Backflow Preventer
This protects individual plumbing fixtures from backflow, such as outdoor faucets. A hose bib backflow preventer is a simple device that screws onto the hose bib. It contains a vacuum breaker, which allows water to flow out of the hose during normal operation. In case of sudden pressure reversal, the vacuum breaker opens and vents to the atmosphere, preventing water reversal inside the hose bib.
Check Valves
This is a one-way valve that keeps water flowing in one direction. It closes if the water tries to flow backward due to pressure changes or other problems. There are different types of check valves. Most are useful for either backflow caused by back pressure or back siphonage, but some check valves are effective for both. Check valves can be used with heating systems, water supply lines, and most appliances in the home.
Vacuum Breakers
These are installed on hose bibs, faucets, and spigots to prevent back siphonage. They admit air into the system if a vacuum forms inside the line. There are two main types of vacuum breakers: atmospheric vacuum breakers, which are suitable for low-risk situations, and pressure vacuum breakers, which are for more robust applications like irrigation systems.
Does your home have a backflow problem? The only way to know is to have a professional plumber test your water supply and plumbing system. An experienced plumber can also guide you on the best ways to solve the backflow problems in your home.