Tips for Rheem Electric Tankless Water Heater Troubleshooting

If you’re lucky enough to own a Rheem electric tankless water heater, you have the convenience of an endless supply of hot water on demand. However, these appliances are still not immune to occasional issues that can arise from complex systems. But don’t worry – our guide on Rheem electric tankless water heater troubleshooting has you covered, so you don’t need to call a professional! In the following sections, we’ll show you some simple techniques to keep your appliance running smoothly and efficiently.

As a homeowner, you depend on your Rheem electric tankless water heater for a continuous supply of hot water. But what happens when it fails to deliver? You step into the shower, turn on the tap, and nothing but cold water flows out.

Or maybe you notice the water pressure has dropped, the hot water supply is insufficient for your needs, or there are strange odors or colors in your water. These problems can be frustrating, but fortunately, many of them can be resolved with simple troubleshooting techniques.

Instead of calling a professional and paying hefty repair fees, you can save time and money by learning how to diagnose and fix the issues yourself.

Moving ahead, we’ll share expert tips and advice for your Rheem electric tankless water heater troubleshooting so you can enjoy hot water whenever you need it.

Common Issues with Rheem Electric Tankless Water Heater and How to Fix Them

No Hot Water

If you’re experiencing no hot water from your Rheem electric tankless water heater, don’t panic, as this is a common issue that can be resolved with some troubleshooting.

One of the first things you should check is the electrical box for your home to make sure the circuit breaker hasn’t tripped. This is especially important for electric models of Rheem hot water heaters, which require a significant amount of power to operate, particularly under severe load.

If you find that the circuit breaker has tripped, simply resetting it can often solve the problem quickly. However, if resetting the circuit breaker doesn’t solve the issue, it could be a sign that a fuse has blown.

Rheem electric tankless water heaters use a glass fuse, which can be prone to breakage if the unit is used extensively at higher temperatures. In this case, you’ll need to replace the fuse to troubleshoot the issue. Once you’ve replaced the fuse, make sure to reset the heater before turning it on again.

Extremely Hot Water

It can be annoying and sometimes dangerous when you turn on the faucet and find the water is scalding hot. There are a few possible explanations for why this might be happening.

The first possibility is that the thermostat is not functioning correctly. The second possibility is that you have set the temperature too high.

rheem electric tankless water heater troubleshooting

First, verify the temperature setting and check that it’s not set too high. If it is, reduce the temperature. If the water temperature is already suitable, the thermostat is probably the cause of the issue. Open the access panel and look to see if there are any loose wires to verify this.

If you don’t find any loose wires, remove the access panel and insulation to look at the thermostat settings. Verify that the temperature on all thermostats is within the range of 115 to 125 degrees. Adjust any temperature variation by using a flathead screwdriver.

Now, put the access panel and insulation back in place and connect the heater to a power source. Test to see if the issue has been resolved! If not, it’s best to call an expert for Rheem electric tankless water heater troubleshooting.

Inadequate Hot Water

If you discover that your Rheem water heater isn’t producing sufficient hot water or if the water temperature is lowered, it could be attributable to the heater’s constraints. In other words, the heater might not be able to keep up with your household’s excessive hot water requirements.

The simplest way to test this theory is to restrict your hot water consumption for a couple of days and keep an eye on the water temperature by using it in limited amounts. If you discover that minimizing your usage increases the water temperature voilà, the problem is solved!

But of course, this isn’t a permanent solution. In order to meet your hot water needs, you should invest in the right-sized heater so you can enjoy hot water without any limitations. However, if you don’t have the budget for that, you will have to do with this Rheem electric tankless water heater troubleshooting method for the time being.

You will need to make some compromises in your daily routine while you save up for a more powerful tankless water heater. For instance, start shaving off a few minutes from your shower or consider switching to a low-flow showerhead. Perhaps, you can even start doing your laundry with cold water!

Bad Odor

In case you detect a funky odor emanating from your electric water heater, bacteria might be the root of the problem. Certain types of bacteria, such as Legionella, can thrive in hot water environments.

To resolve the issue, you need to pay more attention to your tankless water heater’s maintenance. The optimal approach is to eliminate the bacteria by increasing the temperature of the water heater to 135-140 degrees Fahrenheit. Let the heater sustain this temperature for 30 minutes, and all bacteria, including Legionella, will be eliminated.

Once the 30 minutes are up, switch off the heater and let it cool down. Once the water has cooled down, thoroughly flush the tank to remove any remaining bacteria.

With this Rheem electric tankless water heater troubleshooting method, you can keep your water heater free from unwanted bacteria and the unpleasant smell they bring.

Leaking Water

If you notice any water leaks around your water heater, it could be due to several issues, such as broken valves, plumbing defects, or problems with your tank or drain lines. Heating elements and corrosion are usually the key contributors to leaks.

Begin the troubleshooting process by examining the tank for indications of corrosion and loose heating elements. Utilize an element wrench to fix any loose heating elements.

If the tank shows signs of corrosion, it’s crucial to replace it since corroded tanks may pose a safety risk and have the potential to explode. Call a professional if you fail to locate where the leak is coming from.

Brownish Water

Seeing discolored water flowing from the faucet may signify tank or pipe corrosion. The culprit here is the sacrificial anode in the water tank that’s designed to attract minerals and prevent them from corroding the tank.

Think of it as a bodyguard that takes one for the team. However, over time, the anode wears out and stops doing its job, leaving the minerals to corrode the tank freely.

To fix this problem, you need to replace the anode, but don’t whip out your toolbox just yet. This is a technical job that requires the skills of an expert plumber. So, give them a call and tell them about the brownish water. They’ll come over, check the anode, and replace it if needed.

Low Water Pressure

Several causes might contribute to low water pressure, which can be annoying to cope with. Fortunately, resolving the issue is simple. Bypassing your water softener is one way to accomplish this.

To prevent water from entering or leaving the softener while you work, simply push the handle on the rear of your unit. Test if the pressure has been restored by checking the water pressure in a few water taps or shower heads in your household.

If the pressure remains low, the softener is not the culprit, and you may need to hire a plumber. If the pressure rises after bypassing the softener, pour a cleanser through it to remove any impurities, iron, or scale.

Rheem Electric Tankless Water Heater Preventative Maintenance

If you want to avoid using Rheem electric tankless water heater troubleshooting tricks, it’s important to keep up with regular maintenance. By following these few simple tips, you can keep your water heating system in top condition:

  • Keep the heater’s outer unit free of dirt, debris, and lint by regularly cleaning it with a vacuum cleaner.
  • Frequently clean the air filters with water, mild detergent, and a soft-bristled brush.
  • Like air filters, the water filters need cleaning, too, to stay free of dirt and sediment buildup.
  • Flush your tankless water heater annually since it is vital for its longevity. It eliminates any sediment, scale buildup, and debris from the heating element.
  • Schedule an annual inspection of the venting system to ensure it is airtight and secure. If you are not comfortable inspecting the venting system yourself,  hire a qualified plumber to do the job. Check out this video for guidance:


Congratulations! You now have some efficient Rheem electric tankless water heater troubleshooting techniques. You can make sure that your water heater performs smoothly and effectively for many years by adhering to these easy tips and tricks.

But if you ever run into a problem that you are unable to resolve on your own, don’t be afraid to ask a professional plumber for help.

What are you still holding out for? Take charge of your water heating system and reap the rewards of a reliable, high-performance tankless water heater!

With years of experience under his belt, Adam decided to put his water heater knowledge to work. By providing high-quality content and expert guides, Adam hopes to help anyone looking for expert water heater advice.