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how to test a buzzing valve solenoid

Valve solenoids that “buzz” are often caused by inadequate voltage reaching the solenoid.  There can be a few causes for this problem.  Use the simple tests below to evaluate the possible causes and solutions to fix your buzzing valve solenoid.

First, some things you should know:
A valve solenoid is an electromagnetic device that makes an irrigation valve open and close. An irrigation controller (timer) is an automatic electrical control station that sends an electrical 24-volt impulse to the valve along a lead wire.  The circuit is completed by attaching a common wire from the valve back to the controller.

It is normal to audibly hear the solenoid softly buzz when it is turned on and to also hear it click when it is turned on or off. It is NOT normal to hear it make a loud buzzing sound. Below are some questions to help you detemine the cause and solution to remedy your buzzing solenoid.

Are all of your valves operating from the same irrigation controller and do all these valves buzzzzzzzzzzzzzzzzzzzzz?
YES The brand of valves may be slightly louder than other brands, contact the manufacturer to determine if the noise you hear is normal for your model. If the manufacturer says the noise is not normal the problem is most likely either a bad controller or a bad common wire. To check this perfrorm Test 1 below.
YES if only a few solenoid valves in a zone are making a buzzing noise then go to the next question.



Is just ONE (or a couple) solenoids buzzing?

  If only one or two valves are making a buzzing sound it could be those paticular circuits on the controller are faulty. You can check the circuit by switching the wires from a circuit that works into the slot for the valve that has the buzzing solenoid. If the valve no longer buzzes after the wires have been switched then the circuit on the controller is faulty. If there are empty circuits that are functioning you can simply switch the wires into the functioning slots. If the solenoid is still buzzing. You should continue to TEST 2 below and check the wire leads on the valve. If they are ok then the problem looks like it may not be a wiring issue but with the valve or solenoid. Continue then to TEST 4 by cleaning the solenoid and valve. If you still have a buzzing sound coming from your solenoid you should replace the valve guts (or the entire valve in addition to the solenoid.

Purchasing test equipment will make the testing process much easier; however, the tests that follow can be performed by using a homemade valve activator, CLICK HERE TO SEE HOW TO MAKE VALVE ACTIVATOR


Check the wiring from the controller
You can check the wiring from the controller with a electronic repair tool like the model shown below or you can make a simple home made valve activator to check that your wiring is good. To check the wiring with a valve activator you will need to disconnect the common wire (usually white). Then disconnect one of the colored wires from the controller. Now connect both the common wire and the colored wire to your valve activator.

If Solenoid no longer buzzes If the solenoid no longer buzzes the problem is most likely the controller and it will need to be replaced. To test the controller using an electronic repair device simply follow the manufacturer's instructions. If the device will indicate if your controller is faulty.
If Solenoid still buzzes Perfom Test 2



Check the wiring on each valve
Detach your wires on your valves and connect each wire to your valve activator. It does not matter which wire goes on the positive or negative side of your battery made valve activator.

If Solenoid no longer buzzes If the solenoid no longer buzzes the problem is most likely wiring from your controller or the controller itself. Replace the controller.
If Solenoid still buzzes The valve is either dirty or the solenoid is bad.



Check the controller / timer
To check the controller you will need to purchase an irrigation testing device. Follow the manufacturer's instructions on how to operate the device. The repair device will indicate if the controller needs to be replaced. Without a device you can determine if the controller has gone bad by a process of elimination after performing the first 2 tests.



Clean the valve and solenoid.
Turn off the water. Unscrew the solenoid from the valve.With the solenoid removed from the valve turn on the water. It is normal to have water spray out of the place the solenoid was (protect yourself from getting wet from the shooting spray). You may notice bits of debris in the water. If no water is coming out there might be something blocked in the passages underneath where the solenoid was positioned on the valve. To perform a thorough cleaning remove the lid from the valve (normally held on with screws) and clean out the interior of the valve. You may want to make a quick sketch to make sure you re-assemble the valve correctly. Next, clean the solenoid as well as the plunger. Make sure you clean well under where the solenoid was postitioned on the valve. The plunger should easily slide into the solenoid. If it does not move easily in and out or doesn't spring back you will need to replace the valve. Now test the valve again using either an electronic repair tool or a valve acitivator. If your solenoid is still making a buzzing noise the problem is a bad coil in your solenoid. Replace your solenoid as well as your valve. You also can simply purchase the same brand and model of your existing valve and just replace the diaphragm and . If replacing a solenoid it is always a great idea to go ahead and aslo replace the valve at the same time. Once your solenoid goes it is only a matter of time until the parts of the valve start to malfunction too.

If Solenoid no longer buzzes After the valve and solenoid are cleaned the problem was a dirty clogged valve. No further action needs to be taken.
If Solenoid still buzzes The solenoid and or valve needs to be replaced.

Solutions for working around wiring issues...

2-Wire Controllers
You can use a controller that uses only 2 wires. An option if you have at least 2 good wires. The downside is that it is only cost effective if you are operating over 32 valves on these two wires.

Wireless Controllers
These are controllers that transmit a wireless signal to the control valves.

Shop Wireless Controllers by Manufacturer:
Rain Bird
Irritrol Nelson

Battery & Solar Powered Controllers
These controllers are installed at valve locations and are powered using a solar battery charger.
Shop Battery & Solar Powered Controllers:
Double Up Devices or "Add-A-Zone"
are devices that allow you to install two valves on the same wire.

Hand pumps are an invaluable tool when making valve repairs.
Click here to shop.
There are many great electronic repair tools available that can perform a variety of functions to help locate problems quickly in your irrigation system.
Click here to shop.

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