Yes, having two tankless water heaters makes perfect sense for large homes, high-demand households, or when long pipe runs cause delays. They can be piped in tandem to increase capacity, or split into separate zones to serve different areas of your home.
If you have peak demand near or higher than five gallons for a given hour, you should consider using a multi-unit system. Additional tankless water heating units can also be helpful for areas of the house that are a good distance from the water heater.
Plumbers often hesitate to recommend tankless water heaters due to their steep upfront costs, rigorous annual maintenance requirements (such as flushing to prevent mineral buildup), and complex installation. Furthermore, homes often require costly electrical or gas infrastructure upgrades to accommodate these high-demand units.
A 100lb propane tank holds approximately 23.6 gallons of usable propane. Depending on your hot water usage and groundwater temperature, this tank will run a tankless water heater for about 30 to 60 hours of continuous burn time.
Whether two water heaters are better than one depends on your household size, hot water habits, and home layout. Two heaters provide higher capacity and built-in redundancy, but a single, properly sized unit generally costs less and wastes less energy.
For a busy family of 7, you need a high-capacity unit capable of producing at least 11 to 13+ Gallons Per Minute (GPM). This prevents cold water spikes when multiple people are showering or running appliances simultaneously.
Navien is generally considered the higher-quality, premium option for tankless water heaters, prized for its superior stainless steel heat exchangers and built-in recirculation pumps. However, Rheem is an excellent, more budget-friendly alternative known for its strong reliability, more widely available parts, and lower up-front costs.
The main downsides of a tankless water heater are their significantly higher upfront costs, limited hot water flow during simultaneous usage (e.g., showering and running a dishwasher at the same time), and the need for costly annual flushing to prevent mineral buildup in hard water areas.
In freezing temperatures, condensate produced by a condensing tankless hot water heater can freeze inside the drain line, which can cause leakage, operation issues or shutoff. To help keep your indoor tankless water heater from freezing, use a direct vent exhaust & intake system.
Yes, you can run two showers at the same time, but it completely depends on your tankless heater's flow rate (GPM) and the groundwater temperature in your area.
A tankless water heater usually goes cold mid-shower because the water flow drops below the heater's minimum activation threshold, or the system is overloaded by using too many fixtures at once. It can also happen if sediment blocks the filter or the unit is improperly sized.
Yes, you can claim a federal tax credit for qualifying tankless water heaters. Under the Energy Efficient Home Improvement Credit (Section 25C), you can get 30% of the total installation cost (including labor), up to a maximum credit of $600.
The most common problem with tankless water heaters is mineral scale buildup (calcium and magnesium) inside the heat exchanger. This happens when hard water is heated, causing efficiency drops, restricted water flow, and frequent error codes. Regular descaling is required to prevent this.
For tankless water heaters, parallel is vastly superior. A parallel setup divides the water flow between multiple units, reducing strain and increasing your maximum flow rate. A series setup forces water through both units, which restricts flow and ruins energy efficiency.
For a 16x32-foot pool, you will need a heater output of 𝟏𝟕𝟎,𝟎𝟎𝟎 to 𝟒𝟎𝟎,𝟎𝟎𝟎 BTUs, depending on whether you choose a gas heater or a heat pump, how fast you want to heat the water, and whether you use a pool cover.
Plumbers aren't inherently against tankless water heaters, but they often steer clients toward traditional tanks because tankless units are expensive to install, require significant home modifications, and demand strict, costly annual maintenance to avoid voiding warranties.
Yes, you should drip both hot AND cold. Otherwise, the area inside the tankless water heater between the cold water line and the heating element can freeze up and burst (happened to me in 2021 freeze). If you drip both slowly, it ensures all water is running through all the lines.
As temps drop, the risk of having frozen pipes in your home increases. Typical high-risk areas for freezing include pipes within exterior walls, as well as exposed pipes that run through unheated or uninsulated areas such as attics or basements.
Yes, pipes can absolutely burst with a tankless water heater. While tankless units themselves do not have large storage tanks that rupture from pressure, the external supply and exit pipes, as well as the unit's internal heat exchanger, are highly susceptible to freezing.
Navien and Rheem are both premier choices for tankless water heaters, but they excel in different areas: Navien is the premium choice for advanced features and high energy efficiency, while Rheem is the better option if you want reliable, budget-friendly performance.
The average lifespan of a tankless hot water heater is 15 to 20 years. With diligent maintenance and good water quality, high-quality units can even last 20 to 25+ years. This is nearly double the lifespan of traditional tank water heaters, which typically last 8 to 12 years.
Plumbers most frequently recommend Bradford White, A.O. Smith, and Rheem. These brands are favored for their long-term reliability, superior parts availability, and the durability of their internal components.
Rheem is widely considered a top-tier HVAC and water heating brand, frequently ranking in the top 5 to 10 overall HVAC brands. It is highly regarded by industry experts for its excellent reliability, affordable mid-tier pricing, and contractor-friendly designs.
Efficiency: Navien leads with up to 98% thermal efficiency, utilizing condensing technology to reduce energy consumption. Bradford White is reliable but less efficient, generally in the 80-85% range. Features: Navien comes with Wi-Fi capabilities and smart controls, allowing you to monitor usage.