How to Repair Indexing or Sequencing Valves

There are several common issues with indexing valves that we're going to walk through. Since pump and indexing valve combinations are so widely used, I'm going to include some troubleshooting and repair steps that pertain to pumps. If you have a constant pressure municipal water supply, you may have some of the same issues with different steps to rectify. One of the most common issues is contamination in the water, such as sand or grit, and can be remedied by flushing out the valve. Taking off the cam and momentarily turning on the water to get a surge of water to flush out the valve is a great first step. Making sure the pressure and flow rate is ideal will also diagnose a lot of issues. Having a Hose Bibb on the supply line allows one to perform a 5 Gallon Bucket Test quickly or use a Combo Gauge to check pressure and flow. Supply pressure can be checked with a Pressure Gauge and should be between 25 – 75 psi in the case of the K-Rain Valve.

Low Pressure in Zone or Entire System
• Check the Case and Valve Top for leaks
• Verify inlet pressure is within an acceptable range, usually 25 - 75 psi.
• Check any Gate Valves or Ball Valves on the supply line and make sure there're fully
open.
• Check the Solenoid Valve if used for proper operation or blockages.
.
Skipping Zones
• Make sure pressure and flow are within acceptable ranges
• Check the Case and mechanisms for contaminants. Flush and insure that the Stem is
bouncing freely on it's Spring. Clean or replace damaged componenets.
• Insure that the water supply is steady. If a pump is used, check the pump for smooth
consistent operation. A shallow well pump that's losing prime can cause an indexing
valve to quickly advance though one or more zones, appearing to “skip” a zone. A
vacuum gauge on the suction line of the pump can indicate leaks on the suction line or
intake. A Check Valve on the suction line can also stop the problem by holding water
in the body of the pump.
• Check the Cam for damage and proper installation.
.
Low Pressure in Zone or Entire System
• Check the Case and Valve Top for leaks
• Verify inlet pressure is within an acceptable range, usually 25 - 75 psi.
• Check any Gate Valves or Ball Valves on the supply line and make sure there're fully
open.
• Check the Solenoid Valve if used for proper operation or blockages.
Skipping Zones
• Make sure pressure and flow are within acceptable ranges
• Check the Case and mechanisms for contaminants. Flush and insure that the Stem is
bouncing freely on it's Spring. Clean or replace damaged componenets.
• Insure that the water supply is steady. If a pump is used, check the pump for smooth
consistent operation. A shallow well pump that's losing prime can cause an indexing
valve to quickly advance though one or more zones, appearing to “skip” a zone. A
vacuum gauge on the suction line of the pump can indicate leaks on the suction line or
intake. A Check Valve on the suction line can also stop the problem by holding water
in the body of the pump.
• Check the Cam for damage and proper installation.
.
​All Zones Running at Once
• The Stem and Disc aren't seating correctly, remove Cam, flush and observe
• Check inside the Case for any corrosion or scale buildup, particualrly on the lip that
the Disc seats on, and the post that the Stem rests on.
• Check the flow amount, using a 5 Gallon bucket test or Flow Gauge with a faucet on
the supply line
• Check zone pipes for a capped or pinched pipe. Back-pressure into the Valve could
cause all the zones to to get pressure. For this reason, it's not sufficient to just cap off
an unwanted zone. You should also get the proper Cam to match the number of
operational zones.
• Zones with too many sprinklers and too high of a flow demand can cause the Disc to
not seat. Either shut off or nozzle down a few heads to check.