Solenoid valves for car wash systems

Solenoid valves car wash

In car wash installations solenoid valves play a crucial role. A solenoid valve, or magnetic valve, is an electrically controlled valve to control fluid flow (liquids, gases). They are used for various applications in the installation. An example is the mixing of detergent solution or wax. Other examples are the foam brush or tire cleaners.

sample solenoid valves for carwash

Solenoid Valve Maintenance

Solenoid valves in car wash systems are used very intensively and a small defect can cause the entire carwash to stop operating. The key to a reliable operating car wash is using the right parts combined with a good maintenance schedule. It is recommended to inspect the solenoid valves regularly and replace parts periodically to increase the life span and reliability. Car washes which are used intensively, need semi-annual maintenance. This corresponds to 40,000 - 80,000 cycles. Some components, such as the plunger, the spring or the coil, may fail after some time. Therefore, it may be effective to have revision sets available for these components. This is usually more cost effective than the replacement of the entire valve.

Defective solenoid valve

There are several reasons why a solenoid valve is not operating (correctly) anymore. Some common problems:

Dirt in the valve

A solenoid valve can operate poorly due to dirt collected in the valve, small channels may be clogged or the sealing surface may be dirty. This is one of the main reasons why a solenoid valve stops working properly. This problem can easily be solved by opening the solenoid valve and thoroughly cleaning the internal parts with water or with a mild soap solution. To do this, first the power supply must be disconnected, Then, the coil can be removed by loosening a nut or removing a clip. Next, the housing of the valve can be opened. Make sure that the valve is assembled correctly afterwards and tested to make sure everything is working properly. Dirt in the solenoid valve is not a normal situation, so please check if there is a source of contaminants in the environment. Optionally, a filter can be installed in the supply line in order to avoid problems with dirt in the future.

Solenoid valve coil burning out

Another failure mode of solenoid valves is coil failure. The solenoid valve stops operating, because the coil cant generate an electro-magnetic field anymore. A burnt coil is often easy to recognize, but it can be difficult to find the reason why the coil is burnt out. The most common reason is overheating of the coil, this can be caused by insufficient ventilation or too high medium temperatures. It can also be caused by excessive moisture entering the coil, it is also possible that dirt particles in the solenoid valve block movement of the plunger, which can cause a large peak current in the coil. If the coil is burned out, the entire valve does not have to be replaced, only replacing the coil is enough. Make sure that the coil has an IP 65 or higher grade of protection.


Solenoid valves can be affected by corrosion due to the aggressive environment of a car wash system. Use of stainless steel solenoid valves in car wash is advised to increase longevity. However, brass is suitable for most applications with clean water or air, brass is however not suitable for osmosis water. After some time brass will corrode, surface corrosion occurs regularly in high moisture environments. The corrosion often can be removed easily with a mild soap solution. Corrosion on the surface has no influence on the operation of the valve, but in case of heavy corrosion, the material can eventually become brittle and might break. Valves in this condition obviously need to be replaced.

Solenoid Valve Replacement

Sometimes a solenoid valve does not function properly despite a good maintenance schedule. To replace the valve, many car wash owners contact the supplier of the car wash system. However purchasing solenoid valves at a valve specialist is often a more cost effective solution. On the old valve you can find the brand and model number, so an alternative solenoid valve with the same specifications can be easily found.

Additional Information

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