Water Taking Too Long to Heat

Troubleshooting: Why Is My Water Taking Too Long to Heat?

There’s nothing more frustrating than eagerly stepping into a hot shower, only to be greeted by lukewarm or cold water. If you’ve noticed that your water is taking an unusually long time to heat up, it’s important to address the issue promptly. There are several potential reasons why your water heater might be underperforming and here are some common culprits and offer troubleshooting tips to help you get to the bottom of the problem. By understanding the possible causes, you’ll be better equipped to resolve the issue and restore your hot water supply efficiently.

1. Sediment Buildup

As per experts at Andrew Vanny Plumbing North Shore, one common cause of slow water heating is sediment buildup in the water heater tank. Over time, minerals and debris can accumulate at the bottom of the tank, creating a layer that insulates the water from the heating element. This layer acts as a barrier, making it harder for the heating element to transfer heat effectively to the water. Consequently, the water heater has to work harder and take longer to reach the desired temperature.

To address this issue, consider flushing your water heater tank. Start by turning off the power supply or gas valve to the water heater. Next, connect a garden hose to the drain valve at the bottom of the tank and direct the other end to a drain or outside area. Open the drain valve and allow the water to flow until it runs clear. This process will help remove sediment and improve the water heater’s efficiency.

2. Thermostat Issues 

Faulty thermostats can also contribute to extended heating times. A water heater typically has two thermostats—one for the upper heating element and one for the lower. These thermostats regulate the temperature of the water by controlling the heating elements. The plumbers at Andrew Vanny Plumbing North Shore share, if one of the thermostats is malfunctioning, it can lead to inadequate heating or delayed heating.

To check if a thermostat is the culprit, turn off the power to the water heater and use a multimeter to test the thermostats for continuity. If a thermostat fails the continuity test, it’s likely defective and should be replaced. It’s essential to consult the manufacturer’s instructions or seek professional assistance when dealing with thermostat replacements, as the process may vary depending on the specific model.

3. Insufficient Insulation 

Proper insulation is crucial for maintaining the heat within the water heater and its pipes. Inadequate insulation can result in heat loss, causing the water to take longer to heat up. Check if your water heater and the hot water pipes are adequately insulated. If you find any gaps or areas lacking insulation, consider using insulating blankets or foam pipe insulation to reduce heat loss.

Furthermore, pay attention to the ambient temperature surrounding your water heater. If it is located in a cold environment, such as a basement or garage, it may struggle to reach the desired temperature. In such cases, adding extra insulation or considering a water heater blanket can help retain heat and improve heating efficiency.

4. Overworked Water Heater 

If you’ve recently experienced an increased demand for hot water due to changes in household size or usage habits, your water heater might be struggling to keep up. Older or undersized water heaters may take longer to heat water when faced with higher demand.

Evaluate your hot water needs and consider upgrading to a larger capacity water heater if necessary. Alternatively, staggering hot water usage throughout the day or investing in low-flow fixtures can help reduce the strain on your water heater and allow it to heat water more efficiently.

How long does it take to restart hot water? 

Every storage water heater has a certain recovery period. This is how long it takes the tank to start supplying hot water again when it has run out. The following variables can greatly affect the healing time:

  • Tank size: Recovery times are longer for larger tanks.
  • The faster the water heater recovers, the higher the first hour rating (FHR).
  • Fuel type: Electric water heaters reheat almost twice as slowly as gas-powered ones.
  • Rise in temperature: Warm water takes less time to reheat as compared to cold entering water.

There are point-of-use tankless water heaters in addition to whole-house tankless water heaters. These more compact systems, which may be mounted in a sink cabinet or closet, control the hot water output for certain taps. When a water heater can’t adequately supply the entire house, they are a suitable alternative.


When faced with a water heater that takes too long to heat water, it’s essential to investigate potential causes and address them promptly. Sediment build-up, thermostat issues,insufficient insulation, and an overworked water heater are common culprits that can lead to extended heating times. By flushing the tank, checking thermostats, improving insulation, or considering an upgrade, you can improve the efficiency of your water heater and ensure a consistent supply of hot water. Remember, if you’re unsure about any troubleshooting steps or if the problem persists, it’s always wise to consult a professional plumber for assistance.