Sprinkler System Winterization in Iowa

If you have an underground sprinkler system in Cedar Falls, winterizing it is not optional. It is the single most important thing you can do to keep that investment from turning into a repair bill. Water expands when it freezes, and there is a lot of water sitting in the pipes, valves, and sprinkler heads of a typical irrigation system. When that water freezes, it cracks PVC pipes, splits fittings, and blows the seals out of valves. A single hard freeze can do thousands of dollars in damage. The fix is simple: get the water out before the temperature drops and stays down. You have one chance to get it right, and if you miss it, you pay for it in spring.

Professional winterization uses a high-volume air compressor to blow water out of the entire system. The process is straightforward but requires the right equipment and a careful approach. Each zone is activated one at a time, and compressed air is forced through the pipes to push the water out through the sprinkler heads. The air pressure and volume need to be high enough to move the water but not so high that it damages the system. Too much pressure can blow sprinkler heads off their risers or damage the seals in the valves. We use a compressor with a regulator that keeps the pressure in the safe range for residential irrigation components.

The zone by zone process takes about 30 to 45 minutes for a typical Cedar Falls yard. We start with the zone farthest from the compressor and work our way back. Each zone runs until the water stops spraying and only a fine mist of air comes out of the heads. That means the pipe is dry. We repeat this for every zone, including any drip irrigation zones, which are blown out at a lower pressure to avoid damaging the emitters. After the zones are done, we open the manual drain valves at the low points in the system to let any remaining water drain out by gravity. A system that was installed correctly will have those low-point drains in place, and opening them gives the last bit of water a way out.

The backflow preventer needs special attention. This device sits above ground and prevents irrigation water from flowing backward into the household water supply. It is required by code in Iowa, and it is usually the most freeze-vulnerable part of the whole system. Most backflow preventers have test cocks and drain ports that need to be opened to let water out. Some models have removable components that should be taken off and stored indoors for the winter. After the backflow preventer is drained, we wrap it in foam insulation tape and cover it with an insulated bag to protect it through the winter. Even drained, a backflow preventer can freeze and crack if left exposed to the bitter cold.

There is also the controller to deal with. The timer that tells your system when to water needs to be set to the rain mode or turned off for the winter. We also recommend replacing the backup battery in the controller so it holds the program through the winter. Nothing is more frustrating than a dead controller battery in spring when you are trying to reprogram everything. We also note the settings before we change them so your program is ready to go when we do the spring startup. A few minutes of attention in fall saves you an hour of reprogramming in spring.

Spring startup is the other side of the equation. When we come back in April or May, we inspect every component for winter damage, test each zone for proper operation, adjust sprinkler heads that got knocked out of position, and reprogram the controller for the current season. We also check for leaks at the valves and backflow preventer. Catching a small leak in spring is a lot cheaper than letting it run all summer and then wondering why your water bill is twice what it should be. We provide both fall winterization and spring startup for irrigation systems across Cedar Falls, Waterloo, and Black Hawk County. If you have a system that needs blown out before the freeze hits, give us a call and get on the schedule.