Your water heater is one of the hardest-working items in your home. You count on it to provide hot water whenever you need it for showering, washing dishes and performing other tasks. But what happens when a water heater is making a knocking noise? You need a professional plumber to diagnose and address the issue. The experts at Anderson HVAC, Plumbing & Electrical are here to help.
Top Reasons for a Water Heater Making a Knocking Noise
Water heater knocking is exactly what it sounds like: a rhythmic popping or banging sound. If you hear this type of noise, it may indicate anything from a minor issue to a serious mechanical problem. These are some of the most common causes.
Thermal Expansion
Thermal expansion is the result of a natural phenomenon. When heated, water expands, creating pressure within a closed plumbing system. You may hear knocking noises when pressure builds and releases. This often occurs when you’re taking a shower or running multiple appliances.
Sediment Buildup in the Tank
Sediment buildup is one of the top causes of a water heater making knocking noise, especially if you have hard water. Over time, magnesium, calcium and other minerals settle at the bottom of the tank. Water can get trapped beneath a layer of sediment, causing it to boil when the heating element is on. When steam bubbles make their way through the mineral deposits, they can produce knocking, banging or rumbling sounds.
Water Pressure Problems
High water pressure can make a shower feel more luxurious, but it can also cause knocking sounds within your plumbing system. When pressure changes rapidly, it can create what’s known as a “water hammer.” This occurs when water changes direction or stops suddenly. In addition to loud banging, you may notice pipe vibrations or other types of plumbing noises.
Loose Heating Elements
If you have an electric water heater, the heating element is what warms up your water. When it comes loose, it can bang against other parts of the unit, creating knocking or vibrating sounds. A loose heating element can also reduce system performance, making your water heater less efficient.
Scale on Heating Services
The same minerals that cause sediment buildup can also cause scales to form directly on the surfaces inside your water heater. If you have an electric model, the heating element is the most vulnerable component. Gas models tend to form scale directly on their heating surfaces. Mineral scale contributes to overheating, which may cause knocking or popping noises.
Failing Dip Tube
The dip tube is what carries cold water to the bottom of the tank to be heated. If it fails, pieces of loose plastic can move around, causing knocking noises. This is more common in older water heaters.
Why Servicing Your Water Tank Matters
Servicing a hot water tank regularly can prevent many of the issues that cause knocking and banging noises. Regular tune-ups eliminate sediment and make it easier to identify signs that a component is in danger of failing.
Professional service may include:
- Inspecting valves and fittings
- Flushing the tank
- Looking for signs of corrosion
- Checking the burners or heating element
- Testing pressure relief valves
Professional maintenance can help you avoid unwelcome noises, improve energy efficiency and extend the lifespan of your water heater.
Can You Fix a Knocking Water Heater Yourself?
In most cases, you need a professional plumber to fix a knocking water heater. Even small mistakes can create serious safety issues, especially if you have a gas unit. Plumbing systems are also highly pressurized, but an experienced technician knows how to safely make repairs.
When Do You Need Professional Water Heater Repair?
Not every noise indicates a major problem, but you may need professional water heater repair if you notice persistent knocking. Call Anderson HVAC, Plumbing & Electrical if you notice any of these issues:
- Rust-colored water
- Worsening noises
- Leaks around the tank
- Strange odors
- Higher-than-usual energy bills
- Inconsistent hot water
These symptoms may indicate deeper issues, such as corrosion, pressure problems or failing components. One of our technicians can diagnose the cause and recommend appropriate repairs. If your water heater is severely damaged, we can install a new one.
Trust the Experts at Anderson HVAC, Plumbing & Electrical
At Anderson HVAC, Plumbing & Electrical, we’re committed to providing exceptional customer service to residents of the Greater Cleveland Area. We have highly qualified technicians who show up on time, follow local safety codes and clean up after themselves. Call us today if you’ve been dealing with persistent knocking noises from your water heater.
