Here’s what to do if some of the pop-up style sprinkler heads on your landscape sprinkler system do not fully pop-up. It is important to monitor your sprinklers to see if there are any other issues associated with their function.
Sometimes none of the heads fully pop-up, only one or two are partially popping up and the rest are working correctly. This is a fairly common problem, but there are several possible causes to examine.
Many electric solenoid valves used to operate the sprinkler circuits have a flow control handle, knob, or screw-on them that allows the valve to be manually closed or throttled.
If your valves have flow control, check and make sure it is completely open. The flow control on most valves is on top of the valve and centered in the middle of the valve.
There should be a lever (often labeled with “open-close” on it) or a small bleed screw on the valve that allows you to bypass the solenoid and open the valve. If there is a bleed screw open the screw until a small stream of water comes out, but do not remove the screw completely, it is very hard to get back on if you remove it.
In the case that water starts coming out, STOP turning it and retighten it!
If water comes out it is a manual bleed screw used to manually open the valve, no flow control. For the location of the flow control check the valve owner’s manual. (If you don’t have one, search for an owner’s manual at the valve manufacturer’s website.) Many low-cost valves do not have flow control.
Check any other valves to make sure they are fully open. There may be a shut-off valve at the point where your sprinkler system connects to the house water system, check it.
Check all the sprinklers, as a leaking sprinkler near the valve can cause a different sprinkler that is farther from the valve to not fully pop up. If there is leakage between the riser and the cap when the riser is completely up, the riser seal is bad, the riser is scratched, or the cap is scratched.
Turn off the water and try pulling up the riser on the sprinkler with your hand. There will be resistance due to the retraction spring, but the riser should move easily up and down without catching or hanging up. Sometimes the riser on the pop-up and the seal around it become badly scratched from sand particles.
Next, turn on a single valve that has heads that will not pop up. Sometimes a grain of sand will wedge in the gap between the pop-up riser and the cap of the sprinkler, causing the sprinkler riser to jam partway up.
Repeat this 4 or 5 times to loosen and flush out any sand grains caught between the riser and the cap. Check for excessive blow-by of the sprinkler riser. When the riser comes up a small amount of water squirts out of the gap between the riser and the cap, this is called blow-by.
To check the blow-by have someone turn on the sprinkler valve while you watch the riser on the sprinkler as it comes up. A little water gurgling out between the riser and cap is normal. A lot of water coming out between the riser and the cap is not normal.
There may also be a valve where the house water connects to the water company pipes if you have a municipal water supply.
The problem could even trace back to the street and the city will fix the issue. Sometimes issues happen when they are repairing water lines and they can partially close a valve on the pipes, and forget to reopen it.
If you are still not certain, replace one sprinkler with a brand-new sprinkler and then compare it to the others. If the sprinklers have excessive blow-by they should be replaced. Be sure to use the same brand and model of sprinkler heads for replacements. Different brands and models are NOT compatible with each other.
No water should come out from between the riser and the cap when the riser is in the fully extended position. Turn on the sprinklers and check each one for leakage between the riser and cap. Make sure the riser is fully up when you check. If the riser does not come up all the way, pull it all the way up with your hand.
This often happens when new construction occurs nearby and the water system must supply water to more homes or businesses.
When the water pressure drops, the sprinklers may no longer pop-up fully. If you get your water from a water provider, call them and ask if the water pressure in your neighborhood has dropped recently. In the case that it has, ask if this is just a temporary problem that will go away in a few days.
If it doesn’t clear up on its own we would be happy to help here at Houseman. Contact us now to schedule an appointment.