When considering the best water heating solution for your home, one option that often flies under the radar is the indirect water heater. Unlike conventional water heaters that rely on gas or electric burners to heat water directly, indirect water heaters operate by using an external heat source, such as a boiler or furnace. This heat source generates hot water for space heating, and the indirect water heater captures some of that heat to provide hot water for your household. It is a system that works particularly well in homes with existing boilers or hydronic heating systems.
The concept may seem a bit complex at first, but in practice, it can lead to improved energy efficiency, lower long-term costs, and a more abundant supply of hot water, especially during colder months when the boiler is frequently running. On the other hand, indirect water heaters also come with certain limitations, such as a higher upfront cost, potential space constraints, and reduced efficiency during warmer months.
In this article, we will explore the pros and cons of indirect water heaters in great detail, helping you make an informed decision if you’re considering installing one. With 11 significant pros and 9 potential cons, we will cover every aspect of these systems so that you can determine if this type of water heater fits your home’s needs. Let’s dive into the benefits and drawbacks of indirect water heaters, starting with the positives.
Pros Of Indirect Water Heaters
1. Energy Efficiency
The most significant advantage of an indirect water heater is its energy efficiency. Unlike direct water heaters that rely on their own burner or electric heating elements, indirect systems utilize the excess heat from a boiler or furnace. This setup allows the water heater to take advantage of energy that would otherwise be wasted, especially during the colder months when the boiler is actively working to heat the home. With excellent insulation on the storage tank, standby heat loss is also minimized, which means the water heater requires less energy to maintain the desired water temperature. Over time, this leads to lower energy consumption and reduced utility bills, making indirect water heaters one of the most energy-efficient options available.
2. Higher Hot Water Output
One of the standout features of indirect water heaters is their ability to produce large amounts of hot water. Because they are connected to a boiler system that is often much more powerful than a standalone water heater, they can supply a significant volume of hot water, even for large households or homes with high water demand. This is particularly beneficial for families with multiple bathrooms, appliances that require hot water (like dishwashers and washing machines), or even luxury features like jacuzzis or hot tubs. Unlike some systems that struggle to keep up with simultaneous water demands, an indirect water heater can store a substantial amount of water and meet peak usage requirements with ease.
3. Longer Lifespan
Indirect water heaters generally last longer than their direct-fired counterparts. Since they don’t have burners or electric heating elements inside the tank, fewer components are exposed to wear and tear. The system primarily relies on the boiler to provide heat, which keeps the tank itself in better condition over time. The longevity of these systems can range from 15 to 20 years, and in some cases, they may last even longer with proper maintenance. This durability makes indirect water heaters a sound investment for homeowners looking for a long-term solution that will last without frequent repairs or replacements.
4. Lower Maintenance Requirements
Maintenance is one of the major pain points with traditional water heaters, especially with the burners or electric elements that can accumulate scale or corrode over time. Indirect water heaters, however, require much less maintenance because the water is heated indirectly through the heat exchanger connected to the boiler. This means there are fewer parts prone to failure or breakdown. While it is still essential to maintain the boiler and ensure the heat exchanger is functioning correctly, indirect water heaters typically experience fewer problems related to hard water, corrosion, or sediment buildup. This leads to reduced service costs and fewer unexpected breakdowns.
5. Increased Safety
Safety is always a concern with any appliance, especially one that involves heating. One of the significant safety advantages of indirect water heaters is that they do not use direct combustion or electrical elements inside the water tank. This reduces risks associated with gas leaks, electrical fires, or overheating, which can be concerns with traditional water heaters. Because indirect systems rely on the boiler to heat the water, there’s no open flame, gas lines, or electric components in the water tank, which significantly reduces the likelihood of accidents or malfunctions. Indirect water heaters also minimize the risk of carbon monoxide leaks, a common hazard with gas-fired water heaters.
6. Seamless Integration With Existing Systems
If your home already has a boiler for space heating, adding an indirect water heater is an easy and efficient upgrade. These systems are designed to work in tandem with boilers, meaning they can easily tap into the existing heating infrastructure. This makes them a logical and cost-effective choice for homes with hydronic heating systems (radiators or underfloor heating). Installation costs are typically lower in homes with boilers because there’s no need for additional heating components. The indirect water heater becomes an extension of the boiler, sharing the heat output that would otherwise only be used for space heating.
7. Environmentally Friendly
With rising concerns over environmental impact, homeowners are looking for greener options, and indirect water heaters are one such solution. Their energy-efficient operation means they consume less fuel and reduce overall energy waste. Because they piggyback off the boiler’s operation, they make more efficient use of the energy already being produced, lowering the system’s carbon footprint. Additionally, many boilers can now run on cleaner energy sources like natural gas, making the entire system more environmentally friendly. The longer lifespan of indirect water heaters also means fewer resources are required over time for manufacturing, disposal, and replacement.
8. Better Temperature Control
Indirect water heaters are equipped with more sophisticated controls that allow for better regulation of water temperature. Because the system is linked to the boiler, the heat exchanger can be programmed to maintain water at a consistent temperature, which reduces the risk of scalding and enhances user comfort. These systems often work with thermostatic controls that adjust the temperature of the water based on the household’s specific needs, ensuring that the water stays at a safe and comfortable level without fluctuating dramatically.
9. Scalable For Larger Homes
Indirect water heaters are scalable, making them ideal for larger homes or even multi-family units. The performance of the system is closely linked to the size and efficiency of the boiler, so you can choose a system that matches the needs of your household. For homes with large water demands, an indirect water heater can be an excellent option. By selecting a boiler and tank combination that suits your requirements, you can ensure that your household will always have sufficient hot water, no matter how many outlets are in use at once.
10. Silent Operation
One of the often-overlooked benefits of indirect water heaters is their quiet operation. Because they don’t have burners or fans that turn on and off, these systems run quietly, providing hot water without the usual noises associated with traditional water heaters. For homes where noise is a concern, such as in multi-unit buildings or homes with bedrooms near the water heater, this can be a significant advantage.
11. Reduced Peak Demand On Utilities
Because an indirect water heater uses the boiler as its primary heat source, it operates during periods when the boiler is already running, which can often be off-peak times. This means the water heater isn’t constantly drawing on the electrical or gas grid at peak demand periods, helping to reduce overall utility strain. This not only benefits the homeowner through reduced energy bills but also contributes to more efficient energy use across the grid, especially in areas where energy demand is high during certain times of the year.
Cons Of Indirect Water Heaters
1. Higher Initial Cost
One of the significant drawbacks of an indirect water heater is its higher upfront cost. These systems are generally more expensive to purchase than standard direct-fired water heaters. Even though the installation might be easier in homes that already have a boiler, the price of the indirect water heater itself can still be a financial consideration for many homeowners. Additionally, if a boiler system is not already in place, the cost of installing both a boiler and the indirect water heater can become quite substantial, often making it a less viable option compared to traditional water heaters.
2. Requires A Boiler Or Furnace
Indirect water heaters rely on an external heat source—typically a boiler or furnace. This means that for homes without these systems in place, an indirect water heater is not a feasible option unless you plan on installing a boiler at the same time. Homes that use forced-air systems for space heating, such as furnaces, may find it difficult to integrate an indirect water heater without significant modifications. This reliance on a boiler system can be limiting, especially for newer homes that use alternative heating methods or those in warmer climates where boilers are less common.
3. Not Ideal For Warmer Climates
In colder regions, where boilers run frequently during the winter, indirect water heaters perform exceptionally well. However, in warmer climates, where the boiler isn’t running as often or is only used sporadically, the efficiency of the system can drop. During warm seasons, the boiler will need to fire up just to provide hot water, which can negate some of the energy-saving benefits seen in colder months. In such climates, a tankless water heater or other direct-fired systems might be a better solution, as they don’t depend on seasonal boiler use to maintain efficiency.
4. Larger Space Requirements
Indirect water heaters generally take up more space than their direct counterparts. The system includes not only the water storage tank but also the boiler itself, which can make it challenging to find sufficient room, especially in smaller homes or apartments. Space constraints in utility rooms, basements, or closets can become a limiting factor for homeowners interested in this system. Moreover, indirect water heaters are often bulkier because of the insulation and water tank size, which are designed to store large volumes of hot water. This can be a concern for those who are tight on space but still want an efficient water heating solution.
5. Longer Installation Time
The installation of an indirect water heater can be more complex and time-consuming than that of a standard water heater. Connecting the system to the boiler and ensuring it integrates well with the home’s heating setup often takes longer than simply installing a standalone water heater. This can be an issue for homeowners who are in immediate need of hot water or those who wish to keep installation costs and time to a minimum. A more intricate setup means not only longer installation times but also potentially higher labor costs.
6. Boiler Dependency
Since an indirect water heater relies entirely on the boiler to function, any issues with the boiler will directly affect your hot water supply. If the boiler malfunctions or requires maintenance, you could lose both your home’s heating and hot water simultaneously. This can be particularly inconvenient during the winter months, when both heating and hot water are crucial for comfort. This dependency on the boiler adds another layer of complexity to the system and increases the stakes for ensuring your boiler is well-maintained.
7. Energy Efficiency Tied To Boiler Performance
The overall energy efficiency of your indirect water heater is intrinsically linked to the performance of the boiler. If your boiler is old, inefficient, or improperly sized for your home, the water heater will also suffer from reduced performance. In some cases, homeowners may need to upgrade their boiler to fully realize the energy savings that an indirect water heater can provide. This can add to the cost and complexity of the installation, particularly if your boiler is near the end of its useful life and needs replacing.
8. Limited Summer Efficiency
Indirect water heaters excel in winter months when the boiler is running continuously. However, in the summer, when space heating is unnecessary, the boiler must fire up solely to heat the water. This reduces the overall efficiency of the system during warmer months and can lead to higher energy bills during the summer. In contrast, direct water heaters or tankless systems maintain their efficiency year-round, regardless of the season. This seasonal inefficiency may be a deciding factor for homeowners in regions with hot summers.
9. More Complex System
Finally, indirect water heaters are generally more complex than traditional systems. The integration with the boiler means that homeowners need to be familiar with both the water heating system and the boiler’s operation. If a problem arises, it might be more challenging to diagnose and repair without professional help, which could increase operational costs over time. This added complexity may deter some homeowners who prefer simpler, standalone water heating solutions that don’t require an intricate connection to the home’s heating system.
Conclusion
Indirect water heaters are a highly efficient and durable option for households with existing boiler systems, offering benefits such as high energy efficiency, lower maintenance, increased safety, and better scalability for larger homes. Their ability to produce abundant hot water with minimal energy waste makes them an attractive option, particularly in colder climates. However, they are not without their downsides. Higher upfront costs, dependency on a boiler, and decreased efficiency during warmer months may make them less appealing for some homeowners, especially those in areas with limited heating needs or smaller spaces. Ultimately, the decision to install an indirect water heater depends on your home’s specific requirements, the existing heating infrastructure, and your long-term budget.
By carefully weighing these pros and cons, you can determine if an indirect water heater is the right investment for your household’s hot water needs.