Air can get into hot water pipes through several mechanisms, primarily related to the heating process and the water heater itself.
Ways Air Enters Hot Water Pipes
Here's a breakdown of the most common ways air finds its way into your hot water system:
- Air Dissolved in Water: All water contains dissolved air. When water is heated, the solubility of air decreases. This means that as the water gets hotter, it can hold less air, causing the dissolved air to be released as bubbles. These air bubbles can then accumulate and become trapped within the pipes.
- Water Heater Anode Rod Corrosion: The anode rod inside your water heater is designed to corrode instead of the tank itself, thus prolonging the lifespan of the tank. This sacrificial corrosion produces hydrogen gas as a byproduct. This hydrogen can dissolve in the water and may cause bubbling, cloudiness or even a slight odor in your hot water lines.
- Maintenance & Repairs: When plumbing work is performed (repairs, installations, etc.), air is often introduced into the pipes as the system is drained and then refilled. While technicians try to bleed the lines, some air can remain trapped.
- Well Water Systems: Homes with well water may be more susceptible to air in the lines, especially if the well system isn't properly sealed or maintained. Aeration is sometimes used to treat well water, which can introduce air into the system.
Signs of Air in Hot Water Pipes
- Sputtering Faucets: This is a common symptom. When you turn on a hot water faucet, it may sputter or cough out air before water flows steadily.
- Noisy Pipes: Air trapped in pipes can cause banging, gurgling, or whistling sounds, especially when hot water is in use.
- Reduced Hot Water Pressure: Trapped air can restrict the flow of water, leading to a decrease in water pressure at your fixtures.
- Cloudy Hot Water: In some cases, the presence of air bubbles can make your hot water appear cloudy or milky.
Solutions for Removing Air
- Bleed the Lines: Open each hot water faucet in your home, one at a time, and let it run until a steady stream of water flows without any sputtering. Start with the lowest faucet in the house and work your way up.
- Flush the Water Heater: Regularly flushing your water heater helps remove sediment and can also dislodge trapped air. Follow the manufacturer's instructions for proper flushing procedures.
- Check for Leaks: Even small leaks in your plumbing system can allow air to be drawn in. Inspect your pipes, faucets, and fixtures for any signs of leaks.
- Professional Help: If the problem persists, consult a qualified plumber to diagnose and resolve any underlying issues.
