Noise
Air trapped in any water pipes in your home will produce some kind of gurgling or bubbling noise, whether the pipes are part of your hot water heating system or just drain pipes. In most cases this noise is not very loud or bothersome, but as the amount of air in the pipe builds, the noises can become louder and more disruptive.
Pipe Vibration
Symptoms caused by air trapped in your home plumbing lines often lead to assumptions that the problem is water hammer, an issue with different causes and solutions. If your pipes are vibrating or making prolonged noises instead of one loud bang or shake when you turn on a faucet, your problem is trapped air. These vibrations can loosen the pipe fittings that prevent leaks and the straps that keep them from banging against your floor or wall structures. Leaks and loud banging noises may develop if this is the case.
Loss of Water Pressure
Sputtering water when you turn on a faucet is a strong indicator that your pipes have trapped water. Low pressure can also be caused by air bubbles that prevent water from flowing at a higher rate through a specific portion of the plumbing. If the loss of pressure or sputtering flow doesn't disrupt your appliance's functioning, it can be left untreated for a short amount of time without causing further problems.
Blocked Pipes
When an air bubble becomes large enough and is lodged in the right part of the pipe, it can completely block the flow of water. Turning on certain faucets or appliances will simply release the water left between the blockage and the faucet until that section of the pipe empties. Losing water flow to one or more parts of your home is a serious problem. Once your pipes have enough trapped air to stop water flow completely, flushing the system may be the only repair possible.
Rust and Corrosion
If air is entering your plumbing system constantly, as indicated by a return of problems after flushing the system or other repairs, your pipes are at risk. The constant inflow of air into pipes will lead to corrosion such as rust, slowly weakening the pipes and leaving sediment in your water. If you suspect your system has an air leak compromising your pipes, talk to a professional plumber about testing the system and making necessary repairs.