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How Much Does a Whole House Tankless Water Heater Costs?
There are some averages that a person can use to help them determine the cost of the whole house tankless water heater. A tankless water heater that is large enough to provide hot water to the entire home ranges between $1,470 and $2,510. The size of the water heater needed will depend on the size of the home and how many people are in the home to use the hot water. The whole house tankless hot water heater will be around $1,000. Most of these heaters are gas-powered. There are some electric models but for this size, they may be a little harder to find. The hot water heater will have a pilot light and when the system is on it can provide hot water almost instantly.
If a person is looking for a tankless hot water heater they can save some money if they can get an electric one. This model will cost between $800 and $1,600 for installation. There is no need to have vents and they are more energy-efficient. This tankless hot water heater can provide hot water to the entire home.
The tankless hot water heater is going to vary by the brand that a person chooses to purchase. While the average cost is still around $1,000 some brands will not charge as much money. A person should research the brand before making a purchase. They need to make sure that the hot water heater will provide enough water for their home and they are getting a quality product. They should also look and see if the manufacturer is going to offer a warranty on the hot water heater and the duration of this warranty.
Whole House Tankless Gas Water Heater Around $500
- Configured for climates where incoming water temperature can reach as low as 37 degrees.
- Capable of heating nearly 3 gpm.
- Digital temperature control allows temperature settings in 1 degree increments.
- Voltage - 240
- Single phase
Whole House Tankless Electric Water Heater
- Endless Hot Water: Our tankless hot water heaters offer unlimited whole-home hot water flow and come equipped with Circ-Logic for pairing with an external pump to reduce wait time for hot water via scheduled or on-demand recirculation
- Energy and Space Efficient: The tankless design of this small hot water heater saves on space and conserves energy as it heats only when necessary
- Optimal Water Pressure: With a hot water flow rate of up to 11 GPM, this tankless water heater provides a powerful, constant stream that can accommodate up to 7 appliances at once
- Professional Installation Recommended: Visit the Find a Rinnai PRO page on our website to locate a qualified technician in your area to install your water heater; We do not recommend installing a water heater without a technician
- Guaranteed to Last: 15-, 5-, and 1-year residential for heat exchanger, labor, and parts, respectively; Wifi monitoring available with Controlr module (not included)
- ENERGY STAR qualified with Uniform Energy Factor of 0.105
Small Whole House Tankless Water Heater
How Much Does Installation Cost for the Whole House Tankless Hot Water Heater?
In addition to purchasing the whole house tankless hot water heater, a person will need to pay to have it installed. The average installation cost is around $2,000. Some things are going to have an impact on the cost of the installation. This will include the fee for labor from the plumber and the heating equipment that is in the home. Materials and parts needed can add to the cost. A person will also need to purchase a vent kit which is around $100 and there is the piping that is needed that is going to cost around $10 per square foot.
A plumber can charge between $50 and $120 an hour to install a tankless hot water heater. This is for the basic installation. The installation of the tankless hot water heater can take around 3 or 4 hours. The plumber’s fee alone will cost between $150 and $600. Some plumber may also charge an additional estimate fee before they do any work. If they need to remove a hot water heater that is already in the home this will cost around $500.
To make sure that the tankless hot water heater is large enough to handle the demands of the home a person needs to calculate the demand the household has for hot water. They need to look at the BTUs and make sure that the hot water heater can keep up with this. If a person does not understand this they may need the assistance of a plumber but that is going to cost more money.
A tankless water heater for the home is going to have a higher upfront cost. Over time a person can see some savings. They will use less water and less electricity. For most people, this outweighs the upfront cost of having a tankless water heater installed to provide hot water to the entire home.
Frequently Asked Questions
What is the average installed cost of a whole house tankless water heater?
The unit itself runs $500–$1,500 for a quality whole-house model. Professional installation adds $500–$2,000, bringing the typical total to $1,000–$3,500 depending on gas line sizing, venting requirements, and local labor rates.
Is a tankless water heater cheaper to run than a tank heater?
Yes. The U.S. Department of Energy estimates tankless heaters are 24–34% more efficient for homes using 41 gallons or less of hot water daily. Higher-usage households still save 8–14%. Over a 20-year lifespan, energy savings typically more than offset the higher upfront cost.
What drives up the installation cost of a tankless water heater?
Common cost-adders include upgrading to a larger-diameter gas line (required for high-BTU gas units), installing new stainless Category III venting, upgrading an electrical panel for large electric models, and permit fees. These can add $500–$1,500 to the base installation price.
How long does it take a tankless water heater to pay for itself?
Payback period varies by fuel type, usage, and local energy rates, but most homeowners see payback in 5–10 years through energy savings. Federal tax credits on qualifying high-efficiency units can significantly shorten that timeline.
Does a tankless water heater add value to a home?
Yes, generally. Tankless heaters are viewed as a modern upgrade by buyers and appraisers. Energy-efficient appliances often appear as a selling point on listings, and the long lifespan (20+ years) means a tankless unit installed today will likely still be operating when the home sells.