5 Tips for Preventing Water Heaters from Overheating

by Jay | Updated on July 30th, 2022

A water heater is an essential home item. Consider it. How often do you rush into your bathroom after a long day at work to take a long shower? Can your kitchen function without hot water? Not to mention the numerous occasions when you require hot water for laundry.

As a result, it makes perfect sense to keep your heater in the best possible condition so that it can offer you hot water whenever you need it. And we’re not even talking about water supplies.

water heater

Rather, we’d like to concentrate on the water heater itself. More specifically, we will focus on how to deal with an overheating machine. The advice provided below will assist you in dealing with the issue.

How to avoid water heater overheating

1. Examine the temperature settings

Isn’t this a no-brainer? True. However, not many homeowners suspect the temperature settings are the source of the overheating. Water heaters, you see, work differently depending on the model and brand.

Some models include an integrated function that detects problems (including overheating) and alerts you before the problem worsens. Others, on the other hand, lack built-in safety mechanisms.

Whether or whether your tankless heater has an alarm system, you should always keep an eye on the temperature setting. The thermostat should be set between 110 and 125 degrees Fahrenheit when your system is properly functioning. The temperature of the water remains constant within this range.

On the other hand, the thermostat is not perfect and may go over the preset limits. So when your system suddenly generates hot water, you should examine the temperature settings first. Sometimes a simple thermostat adjustment is required to have the heater running properly.

What happens now that the temperature settings aren’t the problem?

So you’ve double-checked your heater’s thermostat, and everything appears to be in working order. Your water, on the other hand, is still hot. In such a case, the only plausible conclusion is that your heating system has experienced a mechanical breakdown. In theory, you’ll need to employ an expert to inspect it.

We should emphasize that you should not examine the heating system unless you know what you’re doing. Most manufacturers will void your warranty if they discover that you tampered with the internal components of your heater, even though you were well aware that you lacked the necessary expertise.

What are the causes of overheating?

If there is an issue with the thermostat or elements, your system is more prone to overheat. This is because elements accumulate sediment deposits when you use your heater, which leads to calcification. The heater must then use more power to heat the water.

In other words, the unit works too hard and eventually fails. When this happens, the water becomes overly hot and continues to heat up if the problem is not corrected.

Here are other reasons why your water heater might be overheating

  1. Sediment accretion

The most prevalent cause of overheating is silt buildup on the surface of the heating units. It is also referred to as calcification. Because of this problem, the heater slows down and loses its early productivity. Although normal wear and tear are unavoidable, failure to maintain the unit can weaken it further and reduce its estimated life.

  1. Thermostat failure

A faulty thermostat can cause water heaters to become unexpectedly and excessively hot. Because the thermostat controls a water heater’s on and off cycle, any fault in this process activates the other processes and disrupts the overall functioning, resulting in overheating.

  1. A lot of minerals

Another unnoticed and passive method a water heater loses a lot of its life expectancy is from high mineral content. Some of the unfiltered minerals in the water interfere with the system’s operation. This can have an impact on both the overheating and the other issues.

Furthermore, the high mineral concentration eventually causes residue and sediment build-up, which degrades the unit over time. As a result, regular cleaning is highly suggested.

How often should I flush my water heater?

The advice is the same whether you have a gas or electric water heater: get the tank cleaned at least once a year. Even tankless water heaters should be cleaned once a year; the hot water that goes through them still tends to produce mineral build-up, even though it is heated on demand and not kept inside the unit.

Consider installing one of our home water purification options to reduce mineral deposits in the future. You’ll also have better-tasting drinking water and cleaner, brighter clothes.

  1. Extremely high temperature

Consistently high temperatures in water heaters might lead to overheating problems in the long run. Maintain the thermostat at the desired and standard temperature.

  1. A pressure valve that has been clogged

A clogged pressure valve causes a pressure of steam to build up within, trapping heat and making it hotter than usual. This is a serious worry because it can make the device prone to mishaps and extremely dangerous to operate.

Furthermore, this is to blame for several heating unit malfunctions. In such instances, you may need to seek expert assistance.

2. Decalcify and clean regularly.

Wiping your heater’s element at least once a year is the most reliable technique to maintain consistent water temperature. The goal here is to remove the sediments and other deposits. We recommend that you make a schedule and keep to it. Make sure to consult your manual for instructions on how to decalcify the inner components.

Keep in mind that the thermostat is prone to tearing and wear. While the best tankless water heater should last for many years, it is also recommended that you change the elements regularly.

3. Examine for mechanical flaws.

Two typical mechanical concerns with tankless water heaters can lead to overheating. First, the thermostat may have a mechanical fault, or the device’s heating elements may be defective.

Impacts might cause these mechanical difficulties. However, scale building is the most prevalent cause of thermostat or heating element dysfunction.

When there is too much scale in the tankless water heater, it has to work harder to heat the water to the desired temperature. On the other hand, when there is enough scale on the unit, it overheats because it cannot heat the water to the temperature set at the thermostat.

The simplest way to avoid this problem is to clean your tankless water heater regularly. In addition, inspecting the unit regularly to verify there has been no impact damage will also help to prevent overheating concerns from damaging your investment.

4. Examine the Release Valves for pressure and temperature.

Check the temperature and pressure release valve frequently to assist you in noticing any potential problems before they worsen. In addition, it is critical to inspect your water heater. If you do not check the heater for an extended period, you may face a fatal explosion in the future. The point we’re trying to make here is that you should do all possible to ensure that the heater is working properly. Don’t wait till it overheats to inspect it.

5. Clear the way for the discharge pipers.

You don’t need specific abilities to achieve this, which is a blessing. In truth, you only need to lift the supply lever for a few seconds to allow the water to clean out the valve. The entire procedure should not take more than a minute. However, if the residue or drainage takes longer, you should contact a plumber to inspect your hot water system.

What if I can’t figure out what’s causing my overheating?

Even after a careful check, some overheating problems can remain a mystery. If you face such a problem, it is a good idea to call your manufacturer’s customer support number, especially if your tankless water heater is new. Something covered by your warranty could resolve this problem.

If your unit is no longer under warranty, seek assistance from a plumber skilled with tankless systems.

Overheating tankless water heaters can cause property damage and human injury. However, frequent inspections and occasional cleaning can avoid many overheating problems.

When should you replace your water heater?

All wonderful things must come to an end at some point. A typical water heater has an intended service life of 8-10 years (20 years for a tankless version). If your water heater is getting on in years and necessitates frequent, costly repairs, it may be time to replace it. Look for a new water heater that is both energy efficient and sized appropriately for your family.


Modern water heaters don’t require much maintenance to keep them running smoothly. Almost every other model we’ve featured in our tankless water heater reviews includes a smart system that alerts you to an increase in water temperature as soon as it occurs. Others can automatically alter the temperature based on the flow of water.

Even so, you should still inspect your water heater regularly. On the contrary, regularly examining the system will help you avoid difficulties. And, as previously stated, always seek the services of a professional plumber if you wish to perform maintenance procedures on your tankless water heater.

Furthermore, ensure that you utilize a water heater with sufficient power to suit your hot water requirements. Using your heater to heat more water than it can handle will certainly break down.

Before investing in a water heater, you should consider the water flow and output vs. what you require in your family. And, as previously stated, after you’ve selected the proper one, it’s your responsibility to ensure that routine maintenance methods are followed to prevent overheating.


Jay is a health and wellness enthusiast with expertise in water quality and nutrition. As a knowledgeable advocate for holistic well-being, Jay successfully manages Type 2 Diabetes through informed lifestyle choices. Committed to sharing reliable and authoritative insights, Jay combines firsthand experience with a passion for enhancing health."