Troubleshooting Solenoid Valves

Fault Finding Solenoid Valves can be quite complex and is best broken down into the three categories of Solenoid Valve Operation. Within each of these categories the solenoid valves are broken up into their resting state namely Normally Closed (power to open) or Normally Open (power to close).

Servo Assisted (Differential)

Normally Closed Servo Assisted

Problem – Normally Closed Valve Solution
Servo assisted solenoid valve does not open.
  • Make sure power is applied (LED) with sufficient amperage for coil.
  • Check that coil voltages are correct for supply (moulded on coil) and the valve label complies Check coil is not `open circuit’ – use multi meter.
  • If ok then check system pressure is above minimum valve operating pressure (on the valve label)
  • If ok then clean or replace diaphragm, check bleed galleries.
Servo assisted solenoid valve does not close.
  • Check that valve has media supply to correct inlet port.
  • Check that power is not applied holding the valve open.
  • If ok then clean or replace diaphragm, check bleed galleries.
Servo assisted solenoid valve is pulsing when activated.
  • Check that valve has media supply to correct inlet port.
  • Check that system pressure is above minimum valve operating pressure (on the valve label)
  • Clean or replace diaphragm, check bleed galleries.
  • Check operator has sufficient `air gap’ and outlet gallery has full flow.
Valve opens when water is first applied to it (without any electrical power).
  • Allow the valve to initially `charge up’ and it will then open and close correctly. This may take 4-5 seconds to fully `charge up’ especially with larger valves.
Valve leaks slightly when first commissioned
  • Strip and clean diaphragm seat and re-test

Normally Open Servo Assisted

Problem – Normally Open Valve Solution
Servo assisted solenoid valve does not close
  • Check that valve has media supply to correct inlet port.
  • Check that coil voltages is correct for supply (moulded on coil) and check that label is correct.
  • Check to make sure power is applied (LED) with sufficient amperage for coil.
  • If ok then clean or replace diaphragm, check bleed galleries.
Servo assisted solenoid valve does not open.
  • Check to make sure power is not applied holding valve closed (LED) – remove plug if necessary.
  • Check that system pressure is above minimum operating requirement.
  • If ok then clean or replace diaphragm, check bleed galleries.
  • If ok then check armature air gap.
Valve is pulsing with no power applied.
  • Check that valve has media supply to correct inlet port.
  • Check that system pressure is above minimum operating requirement (on the valve label)
  • Check operator has sufficient `air gap’ and outlet gallery has full flow.
  • If ok clean or replace diaphragm, check bleed galleries.

 

Direct Acting (zero differential with direct plunger)

Normally Closed Direct Acting

Problem – Normally Closed Valve Solution
Direct acting solenoid valve does not open
  • Make sure power is applied (LED) with sufficient amperage for coil.
  • Check that coil voltages are correct for supply (moulded on coil) and the valve label complies.
  • Check coil is not `open circuit’ – use multi meter.
  • If ok then check system pressure is on.
  • If ok then clean or replace armature.
Valve does not close
  • Check that valve has media supply to correct port.
  • Check to make sure power is not applied holding valve open (LED) – remove plug if necessary.
  • If ok then check valve seat is clean.

Normally Open Direct Acting

Problem – Normally Open Valve Solution
Direct acting solenoid valve does not close Check that valve has media supply to correct inlet port.
Check that coil voltages is correct for supply (moulded on coil) and valve label is complies.
Check to make sure power is applied (LED) with sufficient amperage for coil.
If ok then clean or replace armature.
Valve does not open. Check to make sure power is not applied holding valve closed (LED) – remove plug if necessary.
Check that valve has media supply to correct port.
If ok then clean or replace armature.
Valve is pulsing with no power applied. Check that valve has media supply to correct inlet port.
If ok then check valve seat is clean.

Coupled Diaphragm (zero differential with servo assist)

Normally Closed Coupled Diaphragm

Problem – Normally Closed Valve Solution
Valve does not open
  • Make sure power is applied (LED) with sufficient amperage for coil.
  • Check that coil voltages is correct for supply (moulded on coil) and the valve label complies
  • Check coil is not `open circuit’.
  • If ok then check system pressure is on.
  • If ok then clean or replace armature.
Valve does not close
  • Check that valve has media supply to correct port.
  • Make sure power is not applied holding valve open (LED) – remove plug if necessary.
  • If ok then check valve seat is clean.
Valve is pulsing when activated.
  • Check that valve has media supply to correct inlet port.
  • Clean or replace diaphragm, check bleed galleries.

 Normally Open Coupled Diaphragm

Problem – Normally Open Valve Solution
Valve does not open
  • Make sure power is not applied holding valve closed (LED) – remove plug if necessary.
  • If ok then check system pressure is on.
Valve does not close
  • Check to make sure power is applied (LED) with sufficient amperage for coil.
  • Check that coil voltages is correct for supply (moulded on coil) and check that label is correct.
  • Check coil is not `open circuit’.
  • If ok then check valve seat is clean.
Valve is pulsing when activated.
  • Check that valve has media supply to correct inlet port.
  • Clean or replace diaphragm, check bleed galleries.
  • Check operator has sufficient `air gap’ and outlet gallery has full flow.