Here Are the Possible Causes
Tankless water heaters are an energy-efficient solution that provides endless hot water on demand. They operate without storing large amounts of heated water, which means they only heat water as you need it. While they generally run quietly, you might occasionally hear normal operational sounds during startup or while heating water. However, if your tankless water heater is making unusual noises, especially when no hot water is being used, it may be a sign of a problem that requires professional attention.
Common Causes of Tankless Water Heater Noise
Understanding the source of noise in your tankless water heater can help you address issues early, preventing costly repairs and prolonging the life of your unit.
1. Vacuum Siphoning Water
If you hear loud noises or vibrations when no hot water is running, a vacuum in the plumbing system could be siphoning water away from the heater. This can cause the unit to strain as it attempts to maintain proper water flow. The fix is straightforward: have Grand Lake Plumbing & Heating install a check valve in the water line. This will prevent other plumbing fixtures from interfering with the water heater’s flow and stop the noise.
2. Dirty Flow Sensor
A dirty flow sensor is a common culprit for strange noises. The flow sensor regulates how much gas is sent to the burner to ensure efficient heating. Mineral deposits or debris can cause it to work harder than necessary, producing unusual sounds. Scheduling regular maintenance, including system flushing, can help prevent buildup and keep your heater operating smoothly.
3. Blocked or Inadequate Ventilation
Tankless water heaters require proper ventilation to safely release exhaust gases. If vents are blocked or incorrectly installed, you might hear banging, whistling, or whooshing noises. These indicate the unit is struggling to expel gases, which can lead to reduced performance or dangerous carbon monoxide buildup. If you suspect a ventilation problem, contact us immediately for an inspection.
4. Faulty Pressure Relief Valve
The pressure relief valve is a vital safety feature that prevents dangerous pressure buildup inside the heater. If defective or improperly set, it can cause popping, hissing, or other unusual sounds. Have Grand Lake Plumbing & Heating inspect and adjust the valve to ensure it is functioning properly.
Why You Shouldn’t Ignore Tankless Water Heater Noises
Some sounds are part of normal operation, but excessive or persistent noise may indicate underlying problems. Left unchecked, these issues can lead to:
- Reduced energy efficiency and higher utility bills
- Premature wear and tear on components
- Potential safety hazards, including gas leaks or carbon monoxide exposure
Regular inspections and maintenance will help keep your tankless water heater in top condition, ensuring you always have hot water when you need it.
When to Call a Grand lake Plumbing & Heating
Not every noise requires immediate service, but certain situations mean you should reach out to a licensed plumber right away:
- Persistent noises when no water is running – Could indicate vacuum siphoning or faulty components.
- Sudden changes in water temperature – May signal flow sensor or heating element problems.
- Whistling, banging, or hissing sounds – Often linked to ventilation blockages or pressure issues that can be dangerous.
- Visible water leaks around the unit – Can quickly cause water damage and affect performance.
- Error codes or system shutdowns – Most tankless heaters display error codes when something is wrong; don’t ignore them.
Addressing problems early can prevent major repairs, improve efficiency, and extend the life of your system.
Need Help with Your Tankless Water Heater?
If your tankless water heater is making strange noises, don’t wait for the problem to worsen. At Grand Lake Plumbing & Heating, we specialize in diagnosing and repairing all types of water heaters, including tankless models. Our experienced plumbers will ensure your system is working efficiently and safely, so you can enjoy endless hot water without the hassle.
Contact us today to schedule an appointment or learn more about our water heater services.
Here Are the Possible Causes
Tankless water heaters are an energy-efficient solution that provides endless hot water on demand. They operate without storing large amounts of heated water, which means they only heat water as you need it. While they generally run quietly, you might occasionally hear normal operational sounds during startup or while heating water. However, if your tankless water heater is making unusual noises—especially when no hot water is being used—it may be a sign of a problem that requires professional attention.
Common Causes of Tankless Water Heater Noise
Understanding the source of noise in your tankless water heater can help you address issues early, preventing costly repairs and prolonging the life of your unit.
1. Vacuum Siphoning Water
If you hear loud noises or vibrations when no hot water is running, a vacuum in the plumbing system could be siphoning water away from the heater. This can cause the unit to strain as it attempts to maintain proper water flow. The fix is straightforward: have Grand Lake Plumbing & Heating install a check valve in the water line. This will prevent other plumbing fixtures from interfering with the water heater’s flow and stop the noise.
2. Dirty Flow Sensor
A dirty flow sensor is a common culprit for strange noises. The flow sensor regulates how much gas is sent to the burner to ensure efficient heating. Mineral deposits or debris can cause it to work harder than necessary, producing unusual sounds. Scheduling regular maintenance, including system flushing, can help prevent buildup and keep your heater operating smoothly.
3. Blocked or Inadequate Ventilation
Tankless water heaters require proper ventilation to safely release exhaust gases. If vents are blocked or incorrectly installed, you might hear banging, whistling, or whooshing noises. These indicate the unit is struggling to expel gases, which can lead to reduced performance or dangerous carbon monoxide buildup. If you suspect a ventilation problem, contact us immediately for an inspection.
4. Faulty Pressure Relief Valve
The pressure relief valve is a vital safety feature that prevents dangerous pressure buildup inside the heater. If defective or improperly set, it can cause popping, hissing, or other unusual sounds. Have Grand Lake Plumbing & Heating inspect and adjust the valve to ensure it is functioning properly.
Why You Shouldn’t Ignore Tankless Water Heater Noises
Some sounds are part of normal operation, but excessive or persistent noise may indicate underlying problems. Left unchecked, these issues can lead to:
- Reduced energy efficiency and higher utility bills
- Premature wear and tear on components
- Potential safety hazards, including gas leaks or carbon monoxide exposure
Regular inspections and maintenance will help keep your tankless water heater in top condition, ensuring you always have hot water when you need it.
When to Call a Plumber
Not every noise requires emergency service, but certain situations mean you should reach out to a licensed plumber right away:
- Persistent noises when no water is running – Could indicate vacuum siphoning or faulty components.
- Sudden changes in water temperature – May signal flow sensor or heating element problems.
- Whistling, banging, or hissing sounds – Often linked to ventilation blockages or pressure issues that can be dangerous.
- Visible water leaks around the unit – Can quickly cause water damage and affect performance.
- Error codes or system shutdowns – Most tankless heaters display error codes when something is wrong; don’t ignore them.
Addressing problems early can prevent major repairs, improve efficiency, and extend the life of your system.
Need Help with Your Tankless Water Heater? Call Grand Lake Plumbing & Heating
If your tankless water heater is making strange noises, don’t wait for the problem to worsen. At Grand Lake Plumbing & Heating, we specialize in diagnosing and repairing all types of water heaters, including tankless models. Our experienced plumbers will ensure your system is working efficiently and safely, so you can enjoy endless hot water without the hassle.
Contact us today to schedule an appointment or learn more about our water heater services.
