24V Solenoid Valves – 24V DC and 24V AC Coils
24 volts is the standard control voltage for industrial automation, building services and irrigation. PLC outputs, control panels and most sensors run on 24V DC, while thermostats, irrigation controllers and HVAC transformers usually supply 24V AC. Almost every solenoid valve we sell can be ordered with either coil: choose the voltage on the product page.
24V DC or 24V AC: which coil do you need?
Match the coil to the supply that will switch it. A DC coil on an AC supply will hum and overheat, and an AC coil on a DC supply will burn out, so check before you order.
| 24V DC | 24V AC | |
|---|---|---|
| Typical source | PLC outputs, control panels, 24V power supplies, battery and solar systems | Irrigation controllers, thermostats, BMS and HVAC transformers |
| Behaviour | Silent, steady holding force, little or no inrush current | Higher inrush current at switch-on; the valve's shading ring stops the armature buzzing |
| Things to watch | Switching off creates a voltage spike: use a suppression diode or a DIN connector with a VDR | Size the transformer for the inrush, not just the holding power |
Only have AC but need a DC coil? A bridge rectifier DIN connector lets a DC coil run from an AC supply.
Sizing the power supply
Current is power divided by voltage, so a 10 W coil draws about 0.42 A at 24V DC and a 20 W coil about 0.83 A. Add up every valve that can be on at once and leave some headroom. Coils are rated for ±10% of their nominal voltage, so on long cable runs use a heavier cable to stop the voltage drop leaving the valve short of power.
Our 24V Solenoid Valve Range
All of these ranges are available with 24V DC or 24V AC coils from stock.
| Range | Body | Media | Type | Connection | Pressure |
|---|---|---|---|---|---|
| PU220 | Brass | Water, air, diesel, inert gas, light oil, vacuum | NC + NO, direct acting | 1/8" to 1" BSP | 0 to 12 bar |
| PU225 | Brass | Water, air, diesel, inert gas, light oil | NC + NO + latching | 3/8" to 2" BSP | 0.5 to 15 bar |
| SPU225 | Stainless steel | RO and demineralised water, mildly aggressive fluids | NC + NO + latching | 3/8" to 2" BSP | 0.5 to 15 bar |
| WRAS water valves | Brass and plastic | Drinking water | NC + NO | 8mm push-fit to 1" BSP | Up to 10 bar |
| Plastic valves | Nylon, PVC, PP, PTFE | Water, dilute acids and alkalis | NC + NO + latching | 1/8" to 2" + push-fit | 0 to 10 bar |
| Pneumatic valves | Aluminium, brass | Compressed air | 3/2, 5/2, 5/3 way | M5 to 1/2" BSP | Up to 10 bar |
| VMR gas valves | Aluminium | Natural gas, LPG, biogas (EN161) | NC, auto reset | 3/8" BSP to DN150 flanged | Low pressure gas, to 200 mbar |
| ABVM motorised ball valves | Stainless steel | Drinking water (WRAS) and general water | Open/close or failsafe | 1/2" to 2" BSP | Full bore, no minimum pressure |
Normally closed or normally open?
Normally Closed (NC) → View Products: shut when the coil is off. The usual choice for water and gas shut-off, and fail-safe if the power goes.
Normally Open (NO) → View Products: open when the coil is off. For circuits that must keep flowing unless a signal closes them, such as cooling water.
Replacement 24V coils and wiring
Changing a coil's voltage usually means swapping only the coil, not the valve. Find yours by core size in our solenoid coils range, see the solenoid valve wiring diagram guide for connections, and how to test a solenoid valve if one has stopped switching. Working on a 12 volt system instead? See 12V solenoid valves.