Hot Water Heater Running When Not Using Water

hot water heater

A hot water heater is a crucial appliance in any household, ensuring a steady supply of warm water for various daily activities. However, if you’ve noticed that your hot water heater constantly running, even when you’re not using hot water, it can be concerning. In this blog, we’ll explore the possible reasons behind a hot water heater running all the time and provide some troubleshooting tips to address the issue.

Understanding the Issue: Hot Water Heater Running When Not in Use

Have you ever wondered why your hot water heater keeps running, seemingly without a break? This issue can be attributed to several factors, and understanding them is the first step towards finding a solution.

Common Culprits: Water Heater Constantly Running

a. Thermostat Malfunction

One of the primary reasons for a water heater running all the time is a malfunctioning thermostat. If the thermostat is set too high or has become faulty, it may continuously signal the heating element to keep running.

b. Sediment Buildup

Sediment buildup in the bottom of the tank can lead to reduced efficiency and increased energy consumption. The heating element has to work harder to heat the water, causing the water heater to run constantly.

c. Pressure Relief Valve Issues

The pressure relief valve is a crucial safety component of the water heater. If it malfunctions, it might lead to increased pressure within the tank, causing the water heater to run continuously.

Troubleshooting Tips: Water Heater Keeps Running

a. Check and Adjust the Thermostat

Start by inspecting the thermostat settings. If it’s set too high, lower it to a more reasonable temperature. Additionally, consider replacing the thermostat if it appears to be malfunctioning.

b. Flushing the Tank

Regularly flushing the tank to remove sediment buildup can improve the efficiency of your water heater. Follow the manufacturer’s instructions for flushing, or consult a professional plumber for assistance.

c. Inspect the Pressure Relief Valve

Test the pressure relief valve to ensure it is functioning correctly. If it’s faulty, consider replacing it to prevent excessive pressure in the tank, which can lead to the water heater running all the time.

Electric Water Heater Won’t Stop Running: Addressing Specific Concerns

a. Check the Heating Element

In electric water heaters, a malfunctioning heating element can lead to constant running. Test the heating elements using a multimeter and replace any faulty components.

b. Inspect the Thermostat Wiring

Faulty thermostat wiring can also contribute to the problem. Ensure that all connections are secure and replace any damaged wiring.

Tankless Water Heater Running Constantly: Unique Challenges

For those with tankless water heaters leaking, the challenge may be slightly different. Tankless models are designed to provide hot water on demand, but certain issues can still cause them to run continuously.

a. Check for Flow Sensor Issues

The flow sensor in a tankless water heater regulates when the unit turns on and off. If it’s malfunctioning, the heater may keep running even when hot water is not being used.

b. Verify Proper Sizing

Ensure that your tankless water heater is appropriately sized for your household’s hot water demands. An undersized unit may struggle to keep up, leading to constant operation.


Dealing with a hot water heater that won’t stop running can be frustrating, but by understanding the common causes, you can address the issue effectively and regular water heater service is a best way to avoid the issues. Whether you’re dealing with a traditional tank-style water heater or a tankless model, regular maintenance and prompt repairs can ensure efficient operation and lower energy bills in the long run. If the problem persists, it’s advisable to consult a professional plumber to identify and resolve the issue promptly.