If you use a Reduced Pressure Zone Assembly (RPZ), you ought to schedule a backflow test every year and replace the system once in five years. However, accidents happen, and you may need to change your backflow preventer system even before the due date.
A faulty backflow preventer can poison you, your coworkers, and anyone who patronizes your business. These four signals are telltale signs of a faulty backflow preventer.
The water looks or smells funny
One of the most obvious signs of backflow is contamination. Backflow water will always be dirtier than the water from the correct supply line. This is because the normal flow leads right to the sewers. You can confirm if your water has contaminants by fetching some in a clean glass and letting it sit undisturbed for at least 10 minutes.
The presence of sediments or floating particles indicates that your water is contaminated. You should call your plumber immediately.
The drains are slower than usual
One of the causes of backflow is a pressure shift. Typically, the pressure in the supply line is significantly higher than that in the drain line. This pressure gradient encourages water to move from the tank to the sewer, and not the other way around.
When something disrupts this gradient, water starts to flow backward. This will also make your drains much slower, since the pressure gradient that supports it has failed.
In this case, your drains still work because the draining system relies on gravity as well as the pressure gradient. Water will still flow from your building simply because your drain pipes are facing down. However, you may be knee-deep in water before you realize it. Call your plumber right away.
Rust-colored water
Many things can cause rust in your drinking water, and all of them are dangerous. Rust may make it harder to spot contaminants in water. No matter what, you should call your plumber if you notice rust seeping into your drinking water.
If you aren’t sure if the rust is tied to backflow, check around the backflow assembly system for any signs of leakage.
Leaky assembly device
Your drain system wasn’t designed to flow backward. Spotting leaks around your drain system may mean that your backflow preventer has failed. However, you may also see leaks during a heat wave (due to thermal expansion) or any abnormal changes in your water use.
Most importantly, if your backflow preventer itself is leaking, it is most likely already experiencing a fault. Call your emergency plumbers anytime you notice anything unusual.
Bonus; Where to find your backflow preventer
You can’t spot a bad backflow preventer if you don’t even know where it is. If installed correctly, your backflow preventer should be above the ground, probably near your main control valves. If you have a garden hose or an irrigation system like sprinklers or fire hydrants, your backflow preventer may be somewhere near.