Installing a tankless water heater can provide continuous hot water while saving space and energy, but determining the right safety components can be confusing. If you’ve been puzzling over whether your new electric tankless model requires a pressure relief valve, read on for a detailed breakdown.
If you’re short on time, here’s the quick answer: Yes, a pressure relief valve is required by code for all tankless electric water heaters to prevent explosion risk from excess temperature and pressure buildup.
What is a Pressure Relief Valve and Why is it Needed?
A pressure relief valve is an important safety device that is installed on various types of water heaters, including electric tankless water heaters. Its primary function is to relieve excess pressure and prevent the water heater from exploding or causing other damages.
Definition and Function of a Pressure Relief Valve
A pressure relief valve is a valve that automatically releases pressure from a system when it exceeds a certain level. In the case of a water heater, the valve is designed to release hot water and steam if the pressure inside the tank becomes too high.
The pressure relief valve is typically set to open at a specific pressure, often around 150 psi (pounds per square inch). When the pressure inside the tank reaches this level, the valve opens and allows hot water or steam to escape, relieving the pressure and preventing potential hazards.
Without a pressure relief valve, the pressure inside the water heater tank could continue to rise, potentially causing the tank to rupture or explode. This could result in serious property damage and even personal injury.
Codes Requiring Pressure Relief Valves on Water Heaters
Pressure relief valves are not optional when it comes to water heaters. In fact, they are required by building codes and regulations in most jurisdictions. These codes and regulations are in place to ensure the safety of homeowners and to minimize the risk of accidents.
The International Plumbing Code (IPC) and the National Plumbing Code of Canada (NPC) both require pressure relief valves on water heaters. These codes specify the design, installation, and maintenance requirements for pressure relief valves, ensuring they are installed correctly and function properly.
It is important to note that the specific code requirements may vary depending on the jurisdiction. Therefore, it is recommended to consult the local building codes or a licensed plumber to ensure compliance with the regulations in your area.
Do Tankless Water Heaters Build Up More Pressure?
One common concern among homeowners considering an electric tankless water heater is whether these units build up more pressure compared to traditional water heaters. It is important to understand how tankless water heaters work and their impact on water pressure.
Pressure Buildup in Traditional vs Tankless Water Heaters
Traditional water heaters store a large volume of water in a tank, which means there is always a certain level of pressure inside the tank to maintain a constant supply of hot water. As hot water is used, cold water enters the tank to replace it, leading to pressure changes.
This constant pressure buildup is one of the reasons why traditional water heaters require a pressure relief valve.
On the other hand, electric tankless water heaters do not store water in a tank. Instead, they heat water on-demand as it passes through the unit. This means that there is no constant pressure buildup inside the system.
The water pressure in a tankless water heater depends on the incoming water pressure from the main water supply. Therefore, tankless water heaters do not require a pressure relief valve.
It is worth noting that if the incoming water pressure from the main supply is too high, it is recommended to install a pressure regulator to protect the tankless water heater and other appliances in your home.
Overheating Risks
While tankless water heaters do not build up pressure like traditional water heaters, there is still a risk of overheating if the unit malfunctions. To prevent overheating, most tankless water heaters are equipped with safety features such as temperature sensors and automatic shut-off valves.
These features ensure that the water temperature remains within a safe range and reduce the risk of pressure buildup.
It is essential to have a professional plumber install and inspect your tankless water heater to ensure proper functioning and safety. Regular maintenance, including descaling and cleaning, will also help prevent any issues related to pressure or overheating.
What Kind of Pressure Relief Valve Does My Electric Tankless Model Need?
Pressure Rating
When it comes to selecting a pressure relief valve for your electric tankless water heater, it is crucial to consider the pressure rating. The pressure relief valve should be able to handle the maximum pressure that your water heater can generate.
This is particularly important because if the pressure exceeds the valve’s rating, it may fail to relieve the pressure, leading to potential damage or even explosion of the water heater.
Most electric tankless water heaters operate within a pressure range of 150-200 PSI (pounds per square inch). Therefore, it is recommended to choose a pressure relief valve with a rating of at least 200 PSI to ensure it can handle the highest pressure that your water heater can produce.
Temperature Rating
In addition to the pressure rating, the temperature rating of the pressure relief valve is also crucial. Electric tankless water heaters can generate hot water at high temperatures, and if the pressure relief valve is not designed to handle these temperatures, it may malfunction or become damaged.
The temperature rating of the pressure relief valve should be higher than the maximum temperature that your electric tankless water heater can reach. Most electric tankless water heaters can heat water up to 140-160 degrees Fahrenheit.
Therefore, it is recommended to choose a pressure relief valve with a temperature rating of at least 180 degrees Fahrenheit.
Proper Installation
Installing the pressure relief valve correctly is equally important as choosing the right one. The valve should be installed in a location where it can easily release the pressure and prevent any damage or accidents.
It should be connected to a discharge pipe that directs the water away from people and property.
It is essential to follow the manufacturer’s guidelines and local building codes when installing the pressure relief valve. If you are not confident in your installation skills, it is recommended to hire a professional plumber to ensure the valve is installed correctly.
For more information on pressure relief valves and their installation, you can visit the Hot Water website, which provides detailed guidelines and resources related to water heaters and their components.
Alternatives to Pressure Relief Valves
While pressure relief valves are commonly used in traditional water heaters to prevent excessive pressure build-up, electric tankless water heaters operate differently and may not necessarily require a pressure relief valve.
However, there are alternative measures that can be taken to ensure the safe operation of an electric tankless water heater.
Expansion Tanks
One alternative to a pressure relief valve is the use of an expansion tank. An expansion tank is a separate vessel that is connected to the water heater. It allows for the expansion of water as it heats up, thereby reducing the overall pressure within the system.
This can help prevent any potential damage to the water heater or the plumbing system.
By installing an expansion tank, you can provide a buffer for the increased volume of water that occurs when it is heated. This can help maintain a stable pressure and prevent any sudden pressure spikes.
It is important to note that the size of the expansion tank should be properly matched to the capacity of the water heater to ensure optimal performance.
Careful Temperature Configuration
Another alternative to a pressure relief valve is to carefully configure the temperature settings on your electric tankless water heater. By setting the temperature to an appropriate level, you can reduce the likelihood of excessive pressure build-up.
It is recommended to consult the manufacturer’s guidelines for your specific electric tankless water heater model to determine the recommended temperature range. By maintaining the temperature within this range, you can ensure efficient operation while minimizing the risk of pressure-related issues.
Additionally, regular maintenance and inspections of your electric tankless water heater are crucial to identify any potential issues early on. This can help prevent pressure-related problems and ensure the longevity of your water heater.
Remember, while these alternatives may eliminate the need for a pressure relief valve in some cases, it is important to consult a professional plumber or the manufacturer of your specific electric tankless water heater for guidance on the best approach to ensure safe and efficient operation.
Conclusion
While tankless water heaters are more compact and energy-efficient than traditional models, they still come with exploding risks if not installed with proper safety components like pressure relief valves.
Following manufacturer specifications and plumbing codes by using a valve with adequate pressure and temperature ratings is crucial to prevent accidents and property damage. With the right pressure relief setup, you can enjoy consistent hot water from your new electric tankless heater safely.
