The Truth About Tankless Hot Water HEaters

Tankless water heaters are quickly becoming a common topic of discussion among households across the North Shore and New England, mainly due to their innovative design, which delivers an endless supply of hot water while using significantly less energy than traditional tank water heaters. Unlike conventional systems that continuously heat and store a finite quantity of hot water, tankless heaters operate on demand. This means they activate only when hot water is needed, providing immediate results. Many people wonder about the pros and cons of tankless water heaters, and Fagone is here to help demystify the differences between the two types of systems. 

What are the Main Differences?

When choosing between tank and tankless water heaters, several critical factors must be considered: upfront costs, overall lifespan, hot water availability, and potential repair or maintenance expenses. While tank systems often have a lower initial price point and lower repair costs, tankless systems offer long-term advantages. 

Although the upfront cost of tankless water heaters can be up to twice that of traditional tank models, it's essential to consider their total lifetime cost. These units typically consume less energy, resulting in homeowners using 20% to 40% less energy per year for hot water heating. For households with higher hot-water demand, multiple tankless units may be advisable to ensure an adequate supply, which can affect overall installation costs. Furthermore, while tankless systems may require periodic maintenance and occasional repairs, their reliability often results in fewer unexpected costs. However, when an issue arises, tankless water heaters are usually more expensive to repair. 

Tankless water heaters are an option for homeowners looking to save space or who don’t have the space for a traditional tank water heater. Tankless heaters can be installed in spaces significantly smaller than those required for conventional tank systems, as they do not need a reservoir to hold water for heating. 

The lifespan of a water heater should be a significant consideration when assessing its overall value. Traditional tank water heaters typically have a lifespan of 8 to 10 years, while tankless options are designed to last 15 years or longer, often reaching 20 years with proper maintenance. Additionally, tankless water heaters are less susceptible to corrosion and sediment build-up, which can further extend their functionality. Thus, depending on your plans for the property, such as living there long-term or selling, it’s crucial to consider how your choice of water heater impacts your long-term satisfaction and financial investment.

Tank water heaters can support an unlimited number of fixtures, such as sinks, dishwashers, showers, and washing machines. The only fault is that it can only do so for as long as the tank has hot water; once it runs out, it will need to be refilled and reheated to the temperature specified by the homeowner. Tankless water heaters, meanwhile, have a maximum hot-water capacity. Going over this limit will result in more cold water entering the system than the tankless system can effectively heat to the requested temperature, reducing the heat it can provide to fixtures.

Depending on your climate, a tank or tankless water heater may perform differently. In regions such as the southern and western parts of the United States, water heaters use less energy to heat water to the proper temperature. In the northern parts of the United States, such as New England, the colder climate can make it take more energy to heat water to the homeowner’s specified temperature. In such places, tank water heaters are more common, as tankless water heaters require more energy to heat cold New England water to a hot temperature than in other regions where the water is naturally warmer, such as the Southwest or the West Coast. 

How do Water Heaters make hot water?

Tank and tankless water heaters both produce hot water, but do so in different ways. A traditional tank water heater uses a heating element placed below the tank for natural gas or oil, or an element inside the tank for electric water heaters. These heating elements will raise the temperature to a range that homeowners can use without serious injury. The system uses integrated thermometers to maintain specific water temperatures, and many systems allow homeowners to set the temperature via a digital readout, a dial, or, in some cases, an integrated phone app, such as with Rheem’s EcoNet app. 

Tankless systems open inlet pipes when a home’s hot water demand is requested, such as when a dishwasher or hot water tap is turned on. The water is brought through the tankless system and, using a heat exchanger, is heated to a temperature specified by the system’s owner. The heat exchanger is brought to temperature by an electric heating element in electric systems or by self-regulating gas burners in natural gas systems. Once the water has been brought to temperature within the system, it is released into the house's hot water pipes, where the homeowner can use it. 

Is a Tankless Water Heater Right For Me?

Both tankless and tank water heaters serve the vital role of providing hot water for household activities, but they do so through fundamentally different mechanisms. Tank water heaters operate by maintaining a reservoir of heated water, typically ranging from 20 to 80 gallons, which is used for tasks such as washing dishes, taking showers, and laundering clothes. The process involves heating water over an extended period, meaning there is a delay from the time you turn on the tap until hot water is delivered, as the system needs to refill and reheat the water periodically.

In contrast, tankless water heaters use powerful heating elements to heat water as it flows through the system. This provides a continuous supply of hot water, allowing users to enjoy instant access without the limitations of a storage tank. However, tankless units do have a throughput limit, which varies by model; For instance, many are designed to heat about six gallons of water per minute. This can become problematic when multiple hot water demands coincide, such as running a shower while washing clothes and using the dishwasher. In such cases, the unit may limit hot water flow, resulting in reduced water pressure and potentially disappointing shower experiences. Homeowners can remedy the throughput issues of tankless water heaters with multiple systems, however. The more tankless water heaters in a home, the more hot water can be used per minute, with the obvious drawback being the need to install, maintain, and operate a second system. The give-and-take of the systems is whether you prefer more hot water with the possibility of running out and needing to reheat, or less total hot water but on-demand hot water.

Are Tankless Water Heaters More Energy Efficient?

When it comes to energy efficiency, tankless water heaters have a significant edge over traditional tank systems. According to research from the U.S. Department of Energy, tankless water heaters can cut energy usage by approximately 24% to 34% compared to tank water heaters, particularly for households that consume 41 gallons or less of hot water per day. Interestingly, even in households with higher hot water consumption, tankless units consistently outperform tank units in energy efficiency.

The heightened efficiency of tankless heaters stems from their operational design. Unlike tank water heaters, which maintain a reservoir of hot water at all times using either electric heating elements or a continuously burning pilot light, tankless systems heat water only when needed. As a result, tank water heaters can operate throughout the day, leading to energy waste. In contrast, the instant-on feature of tankless heaters uses energy only when hot water is needed and requires no power to keep water hot for future use.

Do Tankless Water Heaters Cost More To Maintain?

While the initial maintenance costs of tankless water heaters may be higher, their overall reliability often brings the cost of a system over its lifespan into line with that of a traditional tank system. This reliability is attributed to advanced technology, integrated sensors, and modern manufacturing practices that extend the lifespan of tankless systems. Typically, service issues in tankless water heaters are resolved by replacing specific components, avoiding the need for a complete system overhaul. Issues tankless water heaters may experience include mineral buildup on heating elements and pipes (which can be mitigated by installing a water filtration system), malfunctioning elements, inconsistent water temperatures, and failures in the heating system's ability to ignite. These issues, while easier to repair, may be more expensive than repairs to a traditional tank water heater due to the system's complex nature and the higher-cost components inside it.

Alternative Water Heating Solutions

While this blog focuses on tankless and tank systems, many people use other solutions to heat their hot water. Many in New England use a combination boiler, better known as a combi boiler. This system uses hot water to heat the building and provide hot water to plumbing fixtures. This system saves space in the home, simplifies annual maintenance calls, and can provide instant hot water like a tankless water heater. Combi boilers have some disadvantages compared to a dedicated water heating system. Combi system issues can result in the degradation or even total failure of both heating and hot water in a home, as both heat and hot water come from the same system. Additionally, when using the hot-water part of a combi-boiler, there is a temperature difference between the water needed for showering and the water required for home heating. Like with the previously discussed systems, each system meant to heat water for home use has its own strengths and weaknesses. 

Another option is a tankless water heater booster. This is a small, electric water heater that provides a boost in heating to a tank hot water system. It is installed just after the hot water output pipe and provides a small amount of hot water, usually under a few gallons per minute, to the home’s system. For homeowners looking to upgrade their hot water systems but are more than happy with their current tank water heater, unhappy with the amount of hot water it provides before running low, a water heater booster can boost your total hot water output.

Your Local Hot Water Experts

If you're looking for a new water heater —whether you're seeking a tank system, a tankless system, or help deciding between the two — Fagone Plumbing, Heating, & HVAC is here to help. We've helped countless homeowners and families on the North Shore with their hot water needs. We have the expertise and know-how to find the perfect hot water system for your needs. If you're looking for a plumbing partner, Fagone is here to lend a hand. Contact us today for guidance on which hot water solution is right for your home and budget.