Too much of any good thing can be a real problem. While your compressors certainly rely on fresh oil to keep the parts moving smoothly, a compressor flooded with oil is not good. Fortunately, there are only a handful of reasons that your compressor might be flooding, and most of them are easy to fix. Here's what you should look for:
You may not be thinking of airflow when it comes to your compressor's oil, but it is directly related to the issue of flooding. When an air filter gets stopped up, the compressor tries to draw air in from any open port. As such, if it can't get fresh intake air, it will create a vacuum up through the valves in your compressor, actually pulling oil out of the case and up into the intake body. The longer this goes on, the more saturated the filter will become and the more oil you will find in the intake. You will need to properly clean the intake and replace the filter to remedy the problem.
Blocked Oil Return Line
Blocked oil return lines can also cause flooding. Even a small blockage can significantly interrupt the oil's ability to cycle out and around your compressor like normal. The excess oil builds up inside the cylinders until it pushes past the rings. You will notice that your compressor works slower and harder when this is happening because it is operating under so much extra pressure. When your new compressor was installed, the technician should have replaced the oil return or discharge line at that time. If not, you could have years of buildup blocking the outlet.
Another problem we see is oil discharge lines that are too small for the volume of work that the compressor is doing. If you have upgraded your compressor to a higher capacity model, it is possible that the old discharge line is not large enough to handle the faster flow of oil coming from the compressor.
Too Little Load
Another cause of compressor flooding has to do with a compressor operating with not enough load. Compressors are built to be efficient within a certain operating range. If you suddenly reduce the load on your compressor below its normal operating range, it is possible that oil will begin migrating into the low-pressure areas. This is also true if you leave a compressor off for an extended period of time without properly storing it. The oil and refrigerant will begin to migrate and mix, collecting in spaces that it would not be able to reach if it were under a proper load and pressurized with air. The best way to prevent this is to always keep a load on your compressor that is equal to its minimum operating specifications, or have the compressor properly treated before it is shut off for storage.
This problem can also be caused when you purchase a compressor that is too big for the task at hand. At face value, you may think that having a larger compressor will mean that it works faster or does the job better. In reality, it may be costing you more because it cannot ramp up to its peak performance point, and ends up being underloaded at all times. This will cause more problems than it solves in the long run.
Here at Compressors Unlimited, we have seen it all. When your compressor is flooding, give us a call and speak to one of our compressor experts. We can help you identify the causes of your flooding issues and provide you with guidance for how to avoid flooding in the future.