Common Air Compressor Problems and Solutions

Air compressors are critical to many operating and manufacturing processes. Downtime can be costly, significantly impacting the bottom line. Problems with air compressors could be due to many different issues such as air and oil leaks, low pressure, or insufficient airflow.

In most cases, a good service plan and preventive maintenance regime can help you to avoid the problems inherent in any air compressor breakdown. Here, we look at the most common air compressor problems and how to resolve them quickly and effectively through air compressor troubleshooting.

Compressor failure

Is your air compressor failing to start or stop? Probably the most common issue in the industry!

If it won’t start

If it simply won’t start, begin by checking the most obvious causes. A disconnected power cord or a connection switched off at the source. If this isn’t the case, remember to check the breakers.

If all’s well there, check the air pressure. If this is insufficient in relation to the cut-in pressure, the machine may fail to operate. Adjust your settings accordingly. Check your oil too – don’t let it run low.

If it won’t stop

What if it won’t stop? This can be even more alarming. Most air compressors shut down when tank pressure reaches a cut-off point. If this doesn’t happen, you could have a faulty pressure release valve meaning the air compressor is too pressurized to stop. This could cause serious damage to the equipment, so cut the power and either replace the valve or call in the specialists.

Less worryingly, this could also be caused by a faulty power switch – replace the switch! If you’re simply not getting enough pressure to operate the equipment, get your air intake pump checked.  

Electrical issues

This is a bit more complex – it’s probably best to call in the professionals. If your air compressor is regularly blowing fuses and breakers, make sure you’re not connecting it via an extension cord, which can mean the motor struggles for adequate power and overheats. Your compressor should always be connected to a direct power source and not relayed over spaces by extension cords, the power requirement are too great to sustain this long term.

Is your motor past its best? Older, worn motors often exhibit wear and tear and therefore exhibit poor performance alongside a tendency to blow fuses and breakers. Consider changing out the motor if this is a common problem.

If your air compressor lights dim when you start the equipment, remember that this is the stage – often called the inrush – where the air compressor consumes the most power. Your air compressor will have what is known as starter capacitors to overcome this issue. If your lights are dimming at start-up, it might be time to replace these starter capacitors.

Is the air compressor tripping off at start-up? It’s likely to be caused by trapped air. Shut everything off and drain the tank. This should relieve the problem. If the problem persists, get a specialist to look at your unloader valve, which could be faulty and may need cleaning or replacing.

Remember safety at all times with electrical power – if you’re powering down equipment to work on it, ensure you’re up to date with your LOTO (Lock Out, Tag Out) procedures.

Leaking air

Keeping equipment operating in peak condition will save both money and time, so it’s worth checking the efficiency of your compressor regularly for air leaks.

You’ve shut down the air compressor with a full tank and can see the gauge is lower than it should be – you’ve almost certainly got air leaks and your compressor lacks sufficient air pressure. Run all the usual tests to identify the source. You might be able to hear a hissing sound, or even locate the air escaping with your fingertips. If not, apply liquid soap to the connections and look for bubbling, then tighten the connections accordingly.

If the pressure drops further once the compressor tank is switched off, the culprit may be the tank check valve – have it cleaned or replaced to eliminate the air leak.

Flow and pressure issues

Flow problems and low-pressure problems are a little more difficult to see and diagnose. Everything might seem to be in perfect working order, but your air compressor might lose pressure and be compromised. If it’s typically building up to a certain PSI level then the pressure gauge continues to fall, it could be caused by many things – intake and pressure valves, head gasket, and seals. It’s best to have them checked and replaced if necessary.

It’s worth checking your intake filters too to make sure they’re not obstructed, and that your pressure gauge is set correctly.

If you’re just not generating any air pressure, the most likely problem is with the air intake pump or air intake valve. Have it checked and replaced. If the generated air pressure is severely limited, it could simply be a faulty gasket.

Excessive noise or vibration in operation

These are common air compressor problems. Your air compressor has lots of moving components, and it’s only too easy for these to work loose. If the equipment starts making unexpected loud noises or exhibits severe vibrations, you can be sure something is wrong. Quick action will prevent the problem from worsening.

Check for the simple things first – loose components. Adjust pulley bolts and belts accordingly. Make sure the machine is mounted correctly; if it’s not secure, it can move around and shake components loose. If the noises persist, check the crankcase and the oil level. It may need new bearings or just more oil, or it may require complete replacement. Check the pistons, too; if they’re hitting the valve plate, it can cause an alarmingly loud noise.

Prompt action will prevent further damage from loose parts and keep your air compressors running reliably. Consider fitting vibration pads where appropriate to reduce the potential for damage.

The compressor only hums

If your air compressor is just making an ominous humming noise, act quickly – it could be in imminent danger of overheating and significant damage. Throw the power switch!

Check your power supply – as mentioned before, using an extension cord is not recommended; use a direct power supply instead. Also, check your intake air filter. Even if it’s not visibly blocked, try starting the air compressor without it. If this works, you’ve probably located the source of the issue.

Again, it could be your unloader valve – consult the specialists.

Oil issues

Just like your car, running your air compressor on low or no oil (or too much oil) will very swiftly cause significant damage – the oil supply is critical. If you find your oil levels are running low quickly, it could be due to a number of issues – intake obstruction, worn piston rings, and oil leaks. You should check the oil level regularly.

• If the intake is obstructed, clean or replace the filter
• Check the air compressor for oil leaks – they’re usually quite obvious with excessive oil – and rectify
• Replace worn piston rings sooner rather than later
• Wrong oil viscosity – if it’s not right then drain and refill with the correct oil at the proper viscosity.

How do I know when my compressor requires a service?

Most of today’s modern air compressors feature integrated diagnostic tools and internal controls that identify key issues, service requirements, and maintenance prompts. Paying close attention to your air compressor will also pay dividends in terms of performance. Make sure you have a regular inspection routine and act promptly if you identify any issues – the compressor will reward you with continued years of reliable service.

If you run an older machine, there’s nothing more effective than PPM (Planned Predictive Maintenance) and routine maintenance to ensure your compressor continues to run reliably, particularly where it’s an integral part of your processes.

How can CDH help resolve your air compressor problems?

At CDH Group, we specialise in air compressor service plans including preventative maintenance for your compressed air system. If your compressor fails, it can be a big deal. Talk to our engineers – we’ll have a programme to suit your business and your equipment.