A solenoid valve can buzz for several reasons,

typically related to electrical or mechanical issues. Here are some common causes:

1. AC Solenoid Hum or Buzzing

Magnetostrictive: Alternating current (AC) solenoids can experience a slight contraction and expansion of the iron core due to the AC frequency (50Hz or 60Hz). This can cause a low-level hum or buzz.

Loose Components: If the coil, plunger, or any internal parts are loose, they may vibrate more noticeably, increasing the buzzing sound.

Incomplete Plunger Movement: If the plunger is not fully seating due to dirt, limescale, misalignment, or low voltage, it may vibrate, causing a more pronounced buzz.

Voltage Issues: If the supply voltage is too low, the solenoid may struggle to pull in fully, leading to a louder buzzing sound.

Rectifier Issues (DC Solenoid on AC Power): If a rectifier is failing in a DC coil powered by AC, it may lead to incomplete rectification and excessive buzzing.

2. DC Solenoid Buzzing (Less Common)

PWM (Pulse Width Modulation) Control: Some DC solenoids use PWM signals for control, which can create a high-pitched buzzing sound.

Dirty or Worn Plunger: Dirt, corrosion, or mechanical wear can prevent smooth operation, causing oscillation and noise.

Coil Damage: A damaged or overheating coil may cause inconsistent operation, resulting in audible buzzing.

How to Fix It

Ensure the solenoid coil is receiving the correct voltage.

Check for loose screws, mounting, or internal components.

Clean or replace the plunger if it's dirty or stuck.

If using AC power, consider adding a noise suppressor or a rectifier (for DC solenoids).

If the solenoid is worn out, replacing it may be necessary.

Replace with same DC voltage solenoid coil in combination with rectified DIN connector.

Important: If the valve is noisy from new more likely either application issue, if this happened over time more likely debris preventing armature movement especially if used with water as limescale buildup is a common problem.

Tip 1: Try to use a DC voltage solenoid valve, we do stock DC voltage coils from 12vDC to 230vDC, which can be used in combination with a rectified connector to convert AC to DC.

Tip 2: Try our ABVM or ABV motor actuated ball valves.

Would you like help troubleshooting a specific solenoid valve? Contact us. See our FAQ