Air Compressor Pressure Relief Valve Keeps Opening? (Fix It Now!)

Pressure relief valves are an important component of an air compressor. They are basically the last resort in controlling the pressure inside of the compressor. If the pressure relief valve fails, there are no other safety measures. Understanding how it works and why it’s malfunctioning is key to ensuring your safety.

If your air compressor pressure relief valve keeps opening, it’s most likely directing you to a developing compressor issue or an issue with the valve itself. The valve itself might be the problem if the pressure relief valve opens at a lower pressure level than the normal compressor cut out. If it’s opening when the tank level is higher than the normal cut-out, the problem may be with the pressure switch.

Pressure relief valves and safety valves are often confused, but they are not the same. It’s true that a pressure relief valve is there as a safety precaution. But its function is different than that of a safety valve.

The main difference is that a pressure relief valve opens over time in relation to the increasing pressure. A safety valve opens suddenly once the pressure hits the set limit. This is so overpressurization can be avoided.

Below is a comparison chart to note the differences between the two valves.

If the pressure relief valve opens before reaching the maximum pressure allowed for the compressor, it may be a problem with the valve itself.

Sometimes, the air in the tank may get too much oil or water in it, which can then travel to the pressure relief valve. This may lubricate the pressure relief valve innards so much that building pressure overtakes the force of the spring keeping the pressure relief valve closed. The pressure then pushes the valve open before the normal level of air is reached.

What’s the Fix?: To fix this, thoroughly clean the pressure release valve. Shut off the compressor and vent the air from the tank. Take out the pressure relief valve and rinse it in hot water and detergent or a clear solvent. Before reinstalling it, let it dry completely.

If the problem persists after cleaning, you will have to replace the valve.

If your pressure relief valve bleeds air before reaching the normal limit and it’s not between two cylinders, you most likely have a loose valve. The valve may have too much lubrication or the spring may be loose. Pull the pressure relief valve piston and release it. If it doesn’t retract to its original position, the problem is the spring.

Clean the entire valve thoroughly. If that doesn’t fix the problem, it needs to be replaced.

If your pressure relief valve is between two cylinders, there may be a problem with the line between them. First, try cleaning the pressure relief valve as you did in the previous scenario. If that doesn’t work, there might be something blocking the airflow, in which case you can remove it.

We’ve covered a lot of information about the importance of a pressure relief valve and why it may be opening. Below are some other questions people had related to pressure relief valves.

Using a flathead screwdriver, turn the center screw clockwise until you can hear air flow escaping. Turn the screw counterclockwise slowly until the airflow stops. Continue turning the screw counterclockwise for 1/8 to 1/4 turn.

If you turn your AC on and notice loud noises, this could be a sign that the compressor is failing. Other sounds to look out for are any high-pitched noises or grinding sounds. High-pitched squealing can indicate a leaking or worn bearing. Grinding can occur if a bearing has seized.

Typically, a pressure relief valve can last between three and five years. They should be replaced no later than five years.

If you want to replace the valve yourself, the cost can be as little as $20. Calling a professional, however, can up the cost to around $200. If you don’t feel comfortable doing it yourself, it’s highly recommended that you call a professional. Remember, this is the price of your safety.

The pressure relief valve acts as a visual alarm, letting you know something is wrong one last time before there’s danger. For your safety, you must pay attention to it.

If the pressure relief valve keeps opening when the pressure is too high, then the pressure switch is not doing its job. The best solution here is to replace the switch.

If the pressure relief valve keeps opening when the pressure is lower than the maximum allowance, the valve itself needs to either be cleaned or replaced.