Hearing your hot water system making noise is rarely a welcome symphony. Gurgles, hisses, or even bangs often signal a problem, triggering concern and a flurry of questions. Is it dangerous? Will it be expensive to fix? Don’t worry; this article helps you navigate the noisy world of hot water systems.

First, let’s address the elephant in the room – safety. While most noises indicate common and fixable issues, some warrant immediate action. If you detect a gas smell, notice sparks, or see water leaking alongside the noise, immediately turn off your hot water system and the main water supply. Then, contact a licensed plumber without delay. Safety always comes first.

With immediate dangers addressed, we can explore common causes and solutions for those unsettling noises.

What are the Most Common Hot Water Heater Noises?

A symphony of strange sounds emanating from your hot water system is rarely a good sign. Let’s decode those noises and explore their usual suspects and solutions.


What causes it: Popping noises often occur during the heating cycle, especially in systems with tanks. It typically signals sediment build-up at the bottom of the tank. As the sediment heats up, it expands and contracts, creating popping or cracking sounds.

How to fix it:

  • Flush your water heater tank: This process removes accumulated sediment. Consult your system’s manual or a plumber for guidance on flushing.
  • Install a water softener: If you live in a hard water area, consider installing a water softener to prevent future mineral build-up.

If you hear a popping or rumbling sound coming from your hot water tank, especially during heating cycles, it’s often a sign of sediment build-up. Think of it like a kettle boiling with too much limescale. Regular flushing of your hot water tank can prevent this and extend its lifespan.” – Mitch Hook, North East Plumbing.


What causes it: Banging, often the most alarming noise can occur due to several reasons:

  • Water hammer: This occurs when water flow abruptly stops or changes direction, causing a pressure surge and a banging sound in pipes.
  • Loose components: A loose heating element or other internal parts can vibrate and create a banging noise.

How to fix it:

  • Water hammer: Install a water hammer arrestor, a device designed to absorb pressure surges in plumbing.
  • Loose components: Contact a qualified plumber to inspect and tighten any loose parts within the hot water system. They can also make an assessment on whether you need a hot water system replacement.

Many homeowners don’t realise that a sudden spike in water pressure, also known as water hammer, can be the culprit behind those jarring banging noises. Installing a water hammer arrestor is a simple but effective solution that can save you a lot of headaches (and earaches!) in the long run.” – Mitch Hook, North East Plumbing.


What causes it: Ticking sounds are often related to the expansion and contraction of pipes as hot water flows through them. While some ticking is normal, excessive or sudden ticking can indicate a problem.

How to fix it:

  • Check for pipe contact: Ensure pipes are adequately secured and not rubbing against each other or surrounding structures.
  • Insulate pipes: Insulating hot water pipes can minimise expansion and contraction, reducing ticking noises.


What causes it: A high-pitched whistling sound often points to excessive water pressure within the system or a restriction in water flow.

How to fix it:

  • Check water pressure: Use a water pressure gauge to measure your home’s water pressure. If it’s above the recommended range (typically 40-60 psi), install a pressure-reducing valve.
  • Inspect for blockages: Check for mineral deposits or debris restricting water flow in the pipes, valves, or showerheads.


What causes it: Hissing usually indicates a leak within the system. It could be a slow leak from a pipe, valve, or even the tank itself.

How to fix it:

  • Locate and repair the leak: Inspect all visible pipes, connections, and the tank for signs of leaks. Contact a plumber to repair any leaks promptly.


What causes it: A humming sound generally originates from the system’s electrical components, particularly the heating element.

How to fix it:

  • Check for electrical issues: If the humming is excessive or accompanied by burning smells, turn off the power supply to the hot water system and call a qualified electrician or plumber.

Water Running

What causes it: A constant sound of running water, even when no taps are open, strongly suggests a leak within the system.

How to fix it:

  • Locate and repair the leak: Thoroughly inspect all pipes, connections, and the tank for leaks. A plumber can accurately identify and repair the source of the leak.


What causes it: Vibrating noises are often associated with loose mounting straps, especially in tank-style water heaters.

How to fix it:

  • Tighten mounting straps: Check the straps securing the tank to the floor or wall and tighten them as needed.

Remember, these are just some common causes and solutions for hot water heater noises. If you’re uncertain about the cause or solution to your specific problem, always consult with a qualified plumber. Timely action can prevent further damage and ensure the longevity and safety of your hot water system.

Should I Be Concerned About My Hot Water Heater Making Noise?

Should you be concerned if your hot water heater is making noise? It’s a common worry for many homeowners. Hearing hisses, pops, or bangs coming from your hot water system can be unsettling, but it’s not always a sign of a major problem. Some sounds, like a bit of clicking as the system heats up, are perfectly normal, just the pipes expanding and contracting. However, ignoring unusual or persistent noises is never a good idea. These could be early warnings of a developing issue that, if left unchecked, could lead to bigger problems or even safety risks.

A plumber fixing a noisy hot water heater

What Should I Do When My Water Heater Is Making Noises?

Hearing your water heater making strange noises can be disconcerting, but don’t panic. The first step is to assess the situation.

  • Identify the Noise: What kind of noise are you hearing? Is it a popping, banging, hissing, or something else?
  • Determine the Severity: How loud is the noise? Is it a one-time occurrence or frequent? Does it happen only when the water is running or even when it’s off?
  • Check for Visible Problems: Are there any leaks? Do you smell gas? Are any parts loose or damaged?

If you notice any of the following, turn off the water heater and your main water supply immediately and call a qualified plumber:

  • Strong gas odour
  • Water leaking from the unit
  • Sparks or burning smells
  • Loud banging or rumbling noises

For less urgent noises, you can try the following:

  • Consult your water heater manual for troubleshooting tips specific to your model.
  • Check if the pilot light is lit (for gas heaters).
  • Try adjusting the thermostat slightly.

However, it’s always best to err on the side of caution. If you’re unsure about the cause of the noise or how to fix it, don’t hesitate to contact the hot water plumbing experts at North East Plumbing. We have the experience and expertise to diagnose the problem accurately and provide effective solutions, ensuring your hot water system operates safely and efficiently.