How to Check a Solenoid Valve and Fix Common Problems
Whether you’re working with water systems, pneumatic equipment, or industrial automation lines, the brass electric solenoid valve is a small but critical component. When it fails, even the most complex machinery can grind to a halt.
So if you’re wondering:
“Why is my solenoid valve not working?”
“How do I test if a solenoid valve is faulty?”
“Can I repair a solenoid valve myself?”
You’re in the right place.
In this guide, we’ll walk through simple, effective ways to test solenoid valves, troubleshoot issues, and fix common problems — even if you’re not a technician. We’ll keep the language simple and practical, and by the end, you’ll know exactly how to handle a malfunctioning solenoid valve like a pro.
What Is a Solenoid Valve and Why It Fails Matters
A solenoid valve is an electromechanical device that controls fluid or gas flow using an electric current. When energized, the solenoid coil creates a magnetic field to move a plunger, opening or closing the valve.
They’re widely used in:
Water treatment systems
Air compressors and pneumatic lines
Medical devices
Food processing equipment
Textile and printing machines
When a brass electric solenoid valve fails, it can cause:
System shutdowns
Pressure loss or buildup
Product defects or contamination
Unnecessary downtime and maintenance costs
That’s why regular testing and quick repairs are key to keeping your equipment running smoothly.
Top Signs Your Solenoid Valve Might Be Malfunctioning
Before jumping into tests, let’s talk about the most common signs of a faulty solenoid valve:
| Symptom | Possible Issue |
| No flow even when powered | Coil failure, stuck valve core |
| Clicking sound but no movement | Weak magnetic field, blocked spool |
| Leaking fluid or air | Damaged seals, cracked housing |
| Coil overheating | Electrical overload, low-quality coil |
| Inconsistent operation | Loose wiring, faulty plug/socket |
If you’ve seen any of the above, it’s time to do a quick check.
TAMESON also shows the video of 5 most common mulfunctions of Solenoid Valves.
How to Test a Solenoid Valve (Step-by-Step)
Here are practical, real-world methods to check if a solenoid valve is working properly. These apply to most standard brass electric solenoid valves.
🔍 1. Visual Inspection
Start with a simple visual check:
Look for visible cracks on the valve body.
Check if the coil is swollen or discolored (may indicate burnout).
Inspect wires and terminals for signs of damage or loose connection.
🧪 2. Test the Coil with a Multimeter
This test helps you confirm if the coil is good or burned out.
Steps:
- Disconnect power and remove the coil from the valve.
- Set your multimeter to resistance (Ω).
- Measure across the two coil terminals.
What to look for:
24V DC coil → Typically 20–60 ohms
220V AC coil → Typically 800–1600 ohms
If you get 0 (short) or ∞ (open), the coil is damaged.
🧲 3. Magnetic Field Test (No Tools Needed)
If you don’t have a multimeter, try this old-school trick.
Steps:
Power the valve.
Take a small screwdriver and bring it near the top center of the coil.
If you feel magnetic pull, the coil is generating a field.
No magnetic pull? The coil might be dead.
🔧 4. Manual Valve Core Test
This tells you whether the valve spool is moving properly.
Steps:
Power the solenoid valve.
Use a small hex wrench to gently press the brass “pit” or axis hole on the valve.
See if it pulls in (when energized) or releases (when off).
If it doesn’t move, the valve core may be blocked or stuck.
💨 5. Leak Test
Got a compressed air or water source? Great. Here’s how to check for leaks.
Leaks don’t always scream for attention, but they’ll cause long-term problems. If you’ve got access to compressed air or water, do this:
Option 1 – With pressure:
Connect the valve to your system.
Pressurize and energize it.
Spray some soapy water around the joints — bubbles mean leaks.
Option 2 – No gear, no problem:
Block one side of the valve.
Blow gently into the other end (yeah, old-school again).
If air leaks out around the body or threads, there’s a sealing issue.
So, What If It’s Broken? Common Solenoid Valve Problems and Real Fixes
Let’s say you’ve done all the basic checks, and yes — your solenoid valve isn’t doing what it’s supposed to. Maybe it clicks but doesn’t move, maybe it leaks a little, or maybe it just sits there like a useless chunk of brass.
Here’s what usually goes wrong — and more importantly, what you can do about it.
🔥 Problem 1: The Coil Is Dead
How it feels: You power it on, expect that satisfying click, but… nothing. Not even a buzz.
What’s going on:
The coil has probably burned out — maybe from incorrect voltage, maybe from poor cooling. In cheaper valves, aluminum wire coils tend to fail faster than copper ones.
What to do:
Just replace it. Seriously. Trying to “repair” a fried coil isn’t worth the time or risk. Order a replacement that matches the specs — 24VDC or 220VAC, same size, same pin connector. Bonus points if it’s copper-wound.
⚡ Problem 2: Loose Wiring or Bad Plug
Seen this before: The valve works one day, then randomly stops. You wiggle the cable and it suddenly comes back to life. Classic sign of a bad electrical connection.
Solution:
Check if the plug is loose or the socket pins are bent or corroded.
Sometimes, wires inside the connector get mixed up — especially if someone rushed the installation.
Re-seat the connector, trim and re-crimp wires if needed, or just replace the plug.
⚙️ Problem 3: Stuck or Dirty Valve Core
You might notice: The valve clicks, but no fluid passes through. It’s like the path is blocked.
Likely cause:
Dust, rust, or mineral deposits can jam the valve spool. This is especially common in water or compressed air systems with no filtration.
Fix it:
Power off the valve, remove it from the system.
Unscrew the coil and open the valve body.
Wipe or soak internal parts with alcohol or light solvent.
Reassemble and test.
If it still doesn’t move? Might be time for a new valve.
What Tools Do You Actually Need to Troubleshoot a Solenoid Valve?
You don’t need a full lab. Most of the time, a small toolbox and some attention to detail are enough.
Here’s what I personally keep on hand when I need to diagnose a misbehaving brass electric solenoid valve:
🧰 1. Multimeter (Digital or Analog)
Your best friend when it comes to coil testing. Check resistance, voltage, continuity — takes the guesswork out of it.
Pro tip: Don’t just check voltage at the power source. Test at the connector end of the coil too. You’d be surprised how many problems are due to broken wires halfway through.
🪛 2. Small Screwdriver or Hex Key
For:
Removing the coil or unscrewing the plug
Poking the valve core gently to check movement
Avoid using anything too big or sharp — you don’t want to scratch the valve internals.
🧼 3. Cleaning Supplies
Isopropyl alcohol, cotton swabs, compressed air — works wonders when your valve is stuck because of gunk.
💨 4. Air Source (Optional but Nice to Have)
If you have access to a compressor, you can test for air leaks or see if the valve changes state under pressure.
No compressor? Use a small hand pump or — if you’re careful — even your breath.
How to Keep Your Solenoid Valves Healthy (Before They Break)
Here’s a hard truth: most solenoid valves don’t die suddenly. They wear down from bad habits — wrong voltage, dirty air, poor installation. Like your car’s engine, treat it right and it’ll serve you for years.
So let’s talk real-world habits that actually help.
🛡️ 1. Give It a Test Run Every Now and Then
Especially for backup valves or spare systems. A valve left unused for months can freeze up.
Just power it on for 5–10 seconds once a month. That’s enough to keep the magnetic core moving freely.
🧽 2. Clean the Medium — Not Just the Valve
If your water has calcium, or your air line has oil or dust, guess where it ends up? Inside the valve.
Install a proper filter or dryer at the source. It’s a small investment that protects every downstream component.
🔌 3. Watch Your Wiring
Don’t let the cable dangle. Tie it down. Loose wires = unstable current = overheating.
Also, avoid placing valves near motors or heat sources unless they’re rated for it.
🧯 4. Don’t Cheap Out on the Valve
I get it — plastic valves or aluminum coils are cheap. But when they fail (and they will), you’ll spend more time replacing them than saving a few bucks up front.
If it’s for continuous duty or industrial use? Go with brass body + copper coil — and get it from a supplier you trust.
Frequently Asked Questions (And Straight Answers)
Q1: My solenoid valve clicks, but no fluid comes out. What’s wrong?
Good question — that click means the coil is doing its job, but the valve core isn’t moving or the passage is blocked.
Here’s what to check:
Is the inlet pressure high enough to operate the valve? Some valves need minimum pressure to function.
Try removing and cleaning the valve — dirt or rust may be blocking the internal path.
If it still doesn’t work, the valve spool might be damaged or misaligned.
Sometimes, just tapping the body gently while it’s energized will free it — not ideal, but a useful trick for temporary recovery.
Q2: Can I repair a broken solenoid valve, or should I replace it?
It depends on the problem:
Burnt coil? Replace.
Dirty internals or stuck core? Clean and reuse.
Cracked brass body or leaking at the seal? Replace.
Faulty plug or socket? Can be repaired, but only if you’re comfortable with wiring.
In general, small repairs are fine if you know what you’re doing — but for safety-critical applications, replacement is the safer choice.
Q3: How long should a brass solenoid valve last?
With proper use? 3 to 5 years is totally reasonable.
If you maintain it well, filter your media, and avoid overheating the coil — it could last even longer.
However, if your valve fails within months, chances are you either got a low-quality part or the voltage was wrong.
Q4: What voltage should I choose — 24V DC or 220V AC?
Both are common. It depends on your system:
24V DC is safer for low-voltage control panels, mobile applications, or where water is involved.
220V AC is standard in factory automation and industrial equipment.
More important: never mismatch the coil and power source. Running a 24V coil on 220V? It’ll fry in seconds.
Q5: Why is my coil hot to the touch? Is that normal?
A little warmth is fine — solenoid coils generate heat during use.
But if it’s too hot to touch, that’s not normal. Possible causes:
The valve is energized for too long without duty cycle consideration.
Voltage is higher than the rated input.
The ambient temperature is too high.
If you suspect overheating, disconnect power and check the voltage supply. Consider upgrading to a coil with better thermal tolerance.
Q6: Can I use one solenoid valve for both water and air?
Technically yes, but not always ideal.
Some materials behave differently depending on the medium. For example:
Water causes mineral buildup over time.
Air may dry out rubber seals, leading to cracks.
If you frequently switch between media types, choose a valve designed for multi-media use, preferably with high-grade seals and corrosion-resistant internal parts.
Final Thoughts: A Tiny Part That Does Big Work
Solenoid valves might be small, but when they fail, they can bring entire systems to a standstill. That’s why it’s worth taking a few minutes to understand how they work, how to test them properly, and how to spot the early signs of trouble.
Whether you’re in charge of a complex automation line or just maintaining a water control setup, knowing how to troubleshoot a solenoid valve gives you an edge — it saves time, prevents downtime, and protects your investment.
And remember: no matter how good your troubleshooting skills are, the quality of the valve itself makes all the difference in the long run.
So if you’re sourcing solenoid valves for industrial use, go with something reliable — a brass electric solenoid valve with a copper coil, built for durability, pressure tolerance, and long-term performance.
Want help choosing the right one for your system and wanna be distributor/agent of us? TOPO AUTOMATION be happy to assist — just reach out.
