A tankless water heater is a great way to reduce energy costs and save space in your home, but it’s important to understand what other components you may need in order to make it work properly. One of the most common pieces of equipment needed for a tankless water heater is an expansion tank. This tank helps maintain the correct pressure in your system, prevents water hammering, and helps reduce the risk of burst pipes. In this article we’ll discuss why an expansion tank is necessary for a tankless water heater and how it works.A tankless water heater is a type of water heating system that does not use a storage tank to store hot water. Instead, it heats water on demand as it passes through a series of pipes that are heated by gas or electricity. This type of water heater is more efficient than traditional storage tank systems because it only uses energy when hot water is actually needed, rather than keeping a large tank of hot water constantly heated.An
Expansion Tank
is a device used in hydronic heating systems to control the pressure of hot water. It is designed to absorb the expansion of water as it heats up, which can help prevent damage to pipes and other components in the system. The expansion tank works by filling with air or nitrogen gas, allowing for the thermal expansion of water while maintaining a consistent pressure in the system. In some cases, an expansion tank can also provide additional thermal storage capacity, which can be beneficial for reducing energy costs in larger systems. Expansion tanks are an essential component of any hydronic heating system and should be properly sized and installed for optimal performance.
Energy Efficiency
Tankless water heaters are highly energy efficient when compared to traditional tank water heaters. Tankless units only heat the water when it is needed, as opposed to constantly keeping gallons of water hot, which can be an immense waste of energy. This means that homeowners can save on their energy bills significantly by switching to a tankless unit. Tankless units have an Energy Factor (EF) rating that can be up to .99, meaning they are extremely efficient.
Endless Hot Water
Tankless water heaters are capable of providing an endless supply of hot water. Traditional tank units have a limited capacity for storing hot water, so once the tank is empty it needs time to refill and reheat the stored gallons of water. Tankless units can produce up to 3 gallons per minute on demand, so you will never run out of hot water again.
Space Savings
Another great benefit of a tankless unit is that it takes up significantly less space than a traditional tank unit. A standard 40-gallon tank model will take up around 8 square feet in your home, while a tankless model is usually wall-mounted and only takes up around 2 square feet. This makes them perfect for homes with limited space or those looking to maximize their living area.
Longer Lifespan
Tankless units generally last longer than traditional tank models due to their lack of an exposed metal storage container that can corrode over time. The average lifespan of a tankless unit is around 20 years compared to 10-15 years for a traditional model, meaning you will get more out of your investment in the long run.
Does a Tankless Water Heater Require an Expansion Tank?
Tankless water heaters are a great option for many homes and businesses because they are more energy efficient and provide endless hot water. However, there is one component of the traditional tank water heater that is often overlooked when making the switch to tankless – an expansion tank. Expansion tanks are required for all tanked water heaters, including tankless ones, and serve an important purpose in the overall operation of the system.
An expansion tank is a small bladder-type device that is connected to the cold-water supply line and installed near the water heater. Its purpose is to absorb excess pressure from within the hot-water plumbing system, which helps to protect fixtures, pipes, and other components from damage due to thermal expansion. In addition, it helps maintain proper pressure in the system while providing an air cushion for hot water circulation.
The installation of an expansion tank with a tankless water heater can be tricky as it requires special fittings and connections. Additionally, not all models of tankless heaters come with an expansion tank included. If your unit does not have one, then you will need to purchase one separately or hire a professional plumber to install it for you. As with any major plumbing installation or repair job, it is always best to consult with a professional before attempting any work yourself.
In summary, yes, a tankless water heater does require an expansion tank in order to function properly and safely. The installation can be complicated so it is best left to a professional plumber if you are not comfortable doing it yourself.
Why Would You Need an Expansion Tank for a Tankless Water Heater?
Using a tankless water heater eliminates the need for a large, bulky tank. However, it does not eliminate the need for an expansion tank. Expansion tanks are necessary to prevent pressure buildup in your plumbing system when using a tankless water heater. When water is heated, it expands and increases in volume. This increase in volume causes pressure to build up in your plumbing system if there is nowhere for the water to go. An expansion tank allows this extra volume of water to be stored and released when needed, thus preventing excessive pressure from building up in your pipes.
An expansion tank also helps protect your plumbing fixtures from damage due to thermal expansion. As water is heated, it expands and increases in volume, just as with any other liquid or gas. This increase in volume can cause damage to your plumbing fixtures if there is nowhere for the extra volume of water to go. An expansion tank helps absorb this extra volume of water and release it back into the system as needed, thus protecting your plumbing fixtures from damage due to thermal expansion.
In addition, an expansion tank can help reduce wear and tear on your pump by providing a cushion of air between the pump and the closed-off portion of the system that contains high-pressure hot water. This cushion of air helps reduce vibration caused by rapid changes in pressure that can occur when hot water is drawn off quickly from a closed-off portion of the system that contains high-pressure hot water. By reducing vibration, an expansion tank can help extend the life of your pump by reducing wear and tear on its internal components.
Is an Expansion Tank Necessary for a Tankless Water Heater?
Yes, an expansion tank is necessary for a tankless water heater. Expansion tanks are used to capture and store excess pressure that may build up due to thermal expansion in the system. This helps protect pipes from bursting and other damage due to high pressure. If a tankless water heater is installed in a home with a closed plumbing system, the pressure can quickly build up and exceed the capacity of the pipes, valves, and other components. An expansion tank will absorb this excess pressure and release it gradually to prevent unexpected system failure.
The size of the expansion tank you need depends on the size of your tankless water heater and your home’s plumbing system. Generally speaking, larger water heaters require larger expansion tanks. The installation process for an expansion tank is relatively straightforward but should be completed by an experienced professional. Once installed, it should be inspected regularly to make sure it is functioning properly.
In summary, an expansion tank is necessary for a tankless water heater in order to protect the plumbing system from excessive pressure buildup. The size of the expansion tank will vary depending on the size of your tankless water heater and home’s plumbing system, so it’s important to consult with a professional when selecting one for your needs. Regular inspection of the expansion tank is also recommended in order to ensure it is working correctly.
What Happens if You Don’t Install an Expansion Tank for Your Tankless Water Heater?
If you don’t install an expansion tank for your tankless water heater, it can lead to a number of problems. The most immediate issue is the risk of water hammer, which is the sudden and forceful banging noise that occurs when hot water expands quickly in the pipes. This can cause damage to the plumbing system and may even lead to leaks. Additionally, without an expansion tank, you may experience pressure spikes in your water system which can put extra wear and tear on your appliances like toilets and washing machines. This could result in more frequent maintenance or costly repairs over time. Finally, when hot water expands it takes up more space than cold water meaning that over time your pipes can become clogged with built-up pressure leading to reduced flow rates and even complete blockages.
An expansion tank helps to address these issues by providing a place for the hot water to expand without causing damage or putting extra stress on the plumbing system. The tank itself contains a compressed air cushion that absorbs any changes in pressure as hot water expands or contracts. This helps regulate the pressure of your entire plumbing system so that it remains consistent regardless of how much hot water is being used at any given time. Installing an expansion tank is a relatively easy process and it is highly recommended for anyone who has a tankless water heater to ensure their plumbing system stays safe and reliable for years to come.
Installing an Expansion Tank for a Tankless Water Heater
An expansion tank is an important part of any tankless water heater system. It helps to keep water pressure in the system in check and prevents damage to the pipes and fittings. Installing an expansion tank is relatively simple, and can be done by most DIYers with basic plumbing skills. Here’s a step-by-step guide on how to install an expansion tank for a tankless water heater:
1. Begin by turning off the water supply to the tankless water heater and draining the system. This will allow you to access all of the necessary components for installation.
2. Install a shutoff valve between the cold-water supply line and the inlet side of the tankless water heater. This will ensure that you can easily turn off and on water supply to the system when needed.
3. Attach one end of a flexible hose to the shutoff valve, and attach the other end to the inlet side of the expansion tank. Make sure that all connections are secure before moving on.
4. Attach another flexible hose from the outlet side of the expansion tank to one of two ports on top of your tankless water heater. The first port is used for supplying cold water, while the second is used for draining hot water.
5. Install a pressure relief valve between these two ports on top of your tankless water heater if one is not already present.
6. Turn on your main water supply, then turn on each individual shutoff valve connected to your expansion tank until it’s full of air (or you hear it start filling with water). You may need to adjust each shutoff valve until you get it just right.
7. Once your expansion tank is full, turn off each individual shutoff valve until they’re all off, then turn off your main supply line as well.
8. Finally, check all connections one more time before turning on your main supply line again and testing out your new system!
Conclusion
In summary, tankless water heaters do not require an expansion tank. While an expansion tank can help to protect the plumbing system from excess pressure, tankless water heaters are designed to operate at a lower pressure than traditional models. Tankless water heaters can provide hot water on demand and can help to save energy when compared to other models. Furthermore, a tankless water heater may be a better choice for households that have limited space. As such, while an expansion tank is not required, there may be times when installing one is recommended in order to protect the plumbing system and extend its life.
Overall, with their space-saving design and energy efficiency, tankless water heaters offer many advantages over traditional models. While it is not necessary for them to have an expansion tank installed, it may be beneficial in certain cases. Ultimately, the choice of whether or not to install an expansion tank should be based on the individual needs of each household.