There are many troubleshooting solutions for if your Rheem tankless water heater is not heating water, has slow flow, or is tripping your circuit breaker.
Tankless water heaters can save you a lot of electricity and last much longer than the water heaters with tanks.
However, if your Rheem tankless water heater is giving you issues, there are troubleshooting causes and solutions for common problems, which can help you solve problems with cold water, low flow, and continuous breaker tripping.
The benefits of installing a tankless water heater
Where a tank-style water heater continuously uses electricity to heat up the water in the tank, the tankless style only uses electricity when it needs it and this leads to much lower electricity usage and subsequently, a much lower electricity bill.
Installing a tankless or instant water heater in your home can be quite a large upfront investment, but the lower, long-term energy costs can help balance this out.
There are also other benefits associated with the tankless style of water heater, such as fewer leaks, safer operation, and a longer lifespan. These benefits are part of what justifies the higher cost of these units initially for most homeowners.
Troubleshooting Rheem tank-less water heater
Rheem is one of the most well-known brands when it comes to tank-style and tankless water heaters and the brand has high consumer ratings for their tankless water heating systems, such as 4.4 out of 5 from over 1000 customer reviews on this 18 kW tank-less water heater and the same ratings for this 240 V tank-less water heater.
However, this does not mean that the tank-less water heaters from Rheem are faultless. There are still instances where your Rheem water heater may encounter some issues or errors, but fortunately, there are various troubleshooting solutions that you can try to help you identify and fix these issues.
The first step in the troubleshooting process is always to ensure that your Rheem tankless water heater is plugged in and that the circuit is switched on.
You also need to ensure that the temperature is set to 140 degrees Fahrenheit, especially if you are having problems with your water not getting hot enough. The burner light should be blue once you use hot water.
Other troubleshooting solutions for common issues with the Rheem tankless water heaters include the water heater not heating, the water flowing very slowly, and the water heater continuously tripping the circuit breaker.
You can investigate and hopefully solve all of these issues yourself, but you may need a screwdriver along the way to access the service and electrical panels.
Troubleshooting the Rheem water heater not heating water
If your Rheem tankless water heater is not actually heating up your water properly, you can start by looking at the following common causes and solutions for each:
| Possible issue | How to fix the issue |
| Clogged exhaust of air supply system | In order to get your Rheem tankless water heater functioning accurately again, you need to clear and clean any dirt or debris that may be blocking the exhaust or air supply.
You may need gloves, brushes, and trash bags to aid in this process |
| Running too many appliances at once | Try to use less appliances when you need hot water to see if this solves the problem |
| Sediment build-up in the plumbing system | You need to descale your Rheem tankless water heater to remove any sediment build-up in the water heater and its pipes.
This will require distilled white vinegar, a 5 gallon bucket and a circulating pump |
Troubleshooting a Rheem water heater with slow water flow
Some of the troubleshooting solutions in terms of your Rheem tank-less water heater not heating the water properly can also be the cause of low water flow, like sediment build-up in the plumbing and clogged exhausts.
This is why it is important to work through the troubleshooting list one by one to investigate problems.
However, a damaged flow sensor or water control valve may also be the cause of your low water flow issue. In this case, it is best to call a professional, as they will be able to replace any broken components.
Troubleshooting a Rheem water heater that is continuously tripping the circuit breaker
Your circuit breaker may be tripping due to an overload on the system. In this case, you can just flip the circuit breaker on again. However, this can also indicate that there is a problem with the electrical wiring of your tankless water heater or with your switchboard.
It may also be that your thermostat is defective and is switching off your tankless water heater when it should not.