How to Unblock an Air Compressor

What You'll Need
Replacement filter
Pipe cleaner
Cleaning solvent
Replacement check valve

An air compressor is a useful piece of equipment with many different uses. Air compressors can operate pneumatic tools, inflate air bladders, or clear plumbing lines. However, like any piece of equipment, the air compressor requires regular maintenance. Blockages can impede the flow of air or cause the compressor to stop functioning entirely. Luckily, most air compressor blockages can be fixed easily. Generally, you will only need to clean or replace one or two simple parts.

Step 1 – Determine Failure Mode

The manner in which the air compressor failed reveals valuable hints about the source of the problem. If the compressor suddenly shut off, it may have overheated and tripped a safety switch. This problem can be. However, if the only problem is inadequate airflow, there might be a blockage in the check valve. You can verify that this is the problem by inspecting the compressor’s pressure switch. This will leak air of the check valve is clogged. If there are no obvious signs of a leak, coat the area with soapy water. If air is leaking out, bubbles will form.

Step 2 – Replace Air Filter

If the compressor shut off because of overheating, check the air filter cartridge first. Replace or wash the filter regularly according to the manufacturer’s specifications.

Step 3 – Clean Motor Fan

If replacing the filter does not help, or if the filter is not blocked, there may be a blockage on the motor fan. Disassemble the outer housing to expose the motor fan. If there is dust or debris preventing the fan from turning, clean it off. Power up the compressor to see if the fan turns. If it does not, even when clear of blockages, you may need to replace it entirely.

Step 4 – Clean Check Valve

If the problem is a blockage at the check valve, or non-release valve (NRV), clean it or replace it. The check valve resembles two brass nuts. Its function is to prevent backflows of air. Depending on the specific model, it might be threaded on the inside at both ends, on the outside at both ends, or inside at one end and outside at the other. It will be located before the pressure switch and pressure gauge.  The unloader line may also originate here. Disconnect the supply hose from the compressor and remove the check valve. Clean it thoroughly using a wire brush or pipe cleaner, warm water, and a solvent solution. If there is still pressure in the air tank, use compressed air to blow the valve dry. If you are unable to unclog the valve, you can replace it entirely. Check the manufacturer’s specifications to find the correct replacement part. New check valves can cost $20 to $50.

Step 5 – Test Compressor

Reassemble the compressor and attempt to operate it. If these repairs have not worked, then blockage may not be the problem.