24 Hour Emergency Services

Major Compression Mistake You Probably Don’t Know You’re Making

Do you plug the line to the pressure switch? If you do, then you are making a big mistake without knowing. Doing this will prevent your compressor from working properly. Of course you do not want that to happen because that means you will have to spend money to buy a new one that you could have otherwise saved.

If there is one thing you should remember, nothing is connected to your compressor that is not absolutely necessary. So that line coming from your tank near the pressure switch has a specific purpose, and if you plug that line, it will not work in the same way.

Here are some reasons why you should not do this:

You may be confused about this line. So this line, which may be copper or aluminum, is connected to the compressor and into the base of the pressure switch. There is a red triangle that can help you distinguish it. It could start from the fitting to the air line where the pump meets the tank. The large line feeds from the pump. Upon checking the fitting, you’d see that it’s connected to a brass plate and it contains either a check valve or a one-way.


Why is this line important? It is connected to the fitting. The air travels from the pump into that tank because of that fitting. From there the air passes through the smaller line until it finally reaches the pressure switch. This switch has an unloader valve that can either be a part of it or side-mounted. This line from the valve connects to the pressure switch and then connects to the unloader valve. Basically that is how air flows through that line. The pump produces air padding through the line leading to the fitting. Then it flows to the pressure switch. When the unit is running, the unloader valve cannot escape and it is closed. It will then go into the tank, increase pressure, and reach the cut out pressure setting.


When the compressor stops pumping air because of increase in air pressure reaching the cut out pressure setting, the unloader valve then opens. But when there is trapped air in the piston of the pump, it leads to the load of the piston. It may be difficult for the motor of your compressor to start again right after you added this load.


When you plug the line to your unloader valve, it will not start the compressor. It’s because of this trapped air that the cycle of pumping air is stopped. The result? Your compressor could go into a thermal overload. That could progress to a much bigger problem, too.

New mobile red air compressor ready to use.

Partnering with our clients to save
on energy and utilities for future generations!

Learn More