What is an irrigation backflow preventer?
An irrigation backflow preventer is a device used to protect you and your neighbors' drinking water from contamination.
How does contamination occur?
Irrigation systems are plumbed into the same potable water that you drink, thereby creating a potential cross contamination hazard. Contaminated water can end up in your drinking water through back siphonage or back pressure. A backflow device prevents either of these threatening situations from happening.
Where is my irrigation backflow located?
Backflows are typically located outside of your home near your foundation.
What is an irrigation backflow test?
An irrigation backflow preventer has internal springs, check valves and a relief assembly which must be tested when installed, if relocated or repaired and also yearly in St. Louis County.
Dowco test backflows in the spring after the startup to ensure that your backflow is working correctly through the season. We submit all of the appropriate information into the county for you.
Why do we winterize irrigation backflows?
In St. Louis, the cold winter can cause the device to freeze, expand and crack the bronze fittings.
If not shut down properly, the backflow preventer will not pass the test in the spring. Installing a new backflow averages about $700.
What do Dowco’s technicians do during the winterization?
- Shut off the water to your sprinkler system at the main valve. This is typically located in your basement which is why we need you to be home.
- Turn the controller, usually located in the garage, to either “Rain Mode” or “Off”. This allows all of your programming to stay intact so you don’t have to reprogram in the spring.
- Blow out all of the irrigation lines using a large air compressor system. This is one of the most important steps to ensure all of the water is drained from the pipes before cold weather hits.
- Drain the water from your backflow preventer by opening the 4 test cocks.
- Turn the valve on either side of the backflow preventer ¼ so they are not completely open or closed.
How long does an irrigation backflow winterization take?
The technician typically spends about 1 hour on site.
When can I turn the water back on?
Next spring when you’re ready to turn the water on, give Dowco a call to startup the system again!