Quick links
- How Does a Tankless Water Heater Work?
- Tank or Tankless Water Heater: How to Decide
- Are Tankless Water Heaters Worth It?
- Gas or Electric: Which Tankless Type Fits Your Home?
- What Determines Tankless Water Heater Installation Cost
- Choosing the Right Size: GPM, Two Showers and Multi-Unit Buildings
- The Installation Process Step by Step
- Hidden Costs Homeowners Miss With Tankless
- Alternatives That Can Cost Less Than a Whole-House Swap
- How to Compare Two Tankless Quotes
- Timing the Switch: Best Moments to Go Tankless
- Finding a Tankless Water Heater Contractor
- Maintenance and Repair After Installation
- Where You Can Get Help
- Related Plumbing Help
- Frequently Asked Questions
Tankless water heater installation costs more than swapping in another tank because the heater is only part of the job: the gas line, vent, electrical circuit, water piping and permit often change too. That is why tankless water heater cost questions rarely have a single answer, and why the useful question is what in your house will need to change.
Think of what follows as a decision aid rather than a price list. It covers how a tankless unit works, what pushes an installed price up or down, whether the switch is worth it, and how to compare quotes. Exact prices are confirmed by phone after a plumber knows your fuel, layout and demand.
How Does a Tankless Water Heater Work?
How does a tankless water heater work? When you open a hot tap, water flows into the unit, a sensor detects the flow, and a gas burner or electric element heats the water on the spot. When the tap closes, the heat stops. There is no tank of stored water to keep warm.
The same idea by other names
Search phrases like how do tankless water heaters work, how does a tankless hot water heater work, tankless water heater how it works, how do instant water heaters work and demand type water heaters all describe this same on-demand principle. Gas versions add a fan, a burner and a vent. Electric versions use elements and heavy wiring.
What limits the output
Two things cap a unit: how much heat it can add (its burner or element output) and how cold the incoming water is. Colder water means less flow at the same temperature. That is why sizing is done against your coldest month, not your average one.
Tank or Tankless Water Heater: How to Decide
Tank or tankless water heater is a fit question. A tank is cheaper to buy and install in a house set up for one, but it stores and reheats water and eventually corrodes. A tankless unit avoids storage, but demands more from the gas or electrical service.
Is a tankless water heater better?
Is a tankless water heater better for everyone? No. It tends to suit households with modest, steady demand, homes short on floor space, and owners who plan to stay long enough to recover the extra installation work. It suits others less: very large families, homes with weak gas or electrical service, and places with harsh water and no plan for descaling.
Tankless hot water heater vs traditional
- Tankless: compact, no standby heat loss, continuous hot water within flow limits, more complex installation
- Traditional tank: lower equipment cost, simple swap, stored reserve, standby heat loss, tank that can leak
- Both: benefit from a professional install, flushing and a permit where required
For the tank side of the decision, see water heater replacement.
Are tankless water heaters more efficient?
Are tankless water heaters more efficient than tanks? They avoid standby losses, so they can use less energy in some households, particularly those with light hot water use. Do tankless hot water heaters save money? Sometimes, but savings depend on your fuel prices, usage and the added installation work. Avoid any promise of a specific payback; compare using your own bills.
Water still running or a smell of gas? Act first, then call.
Call 417-261-5030Are Tankless Water Heaters Worth It?
Are tankless water heaters worth it comes down to five questions:
- Can your gas line or electrical panel support one without a large upgrade?
- Will you stay in the home long enough to see the benefits?
- Do you value space savings or endless hot water in a single draw?
- Is your water hard, and will you commit to descaling?
- Does your household use hot water heavily and all at once?
Lifespan and life expectancy
Tankless water heater lifespan and tankless water heater life expectancy searches come up often because the marketing suggests these units last longer than tanks. They often do, when maintained, since they can be serviced and parts replaced, but water quality and flushing schedules make a big difference. Manufacturer warranty terms give a hint, not a promise.
Reviews and rankings
Tankless water heater reviews, tankless water heater ratings reviews, best tankless water heaters and top tankless water heaters can help you shortlist, but a review cannot see your gas line or panel. Read them for common complaints, then ask a plumber whether the model suits your house. The same goes for electric tankless water heater reviews, electric tankless hot water heater reviews and the best tankless gas water heater.
Gas or Electric: Which Tankless Type Fits Your Home?
Tankless gas water heater vs electric, or tankless hot water heater electric vs gas, is really a question about what your house can supply. Gas or electric tankless water heater decisions also touch venting and power.
Gas: natural gas and propane
A tankless gas water heater installation needs an adequate gas line, a vent and combustion air, plus a small electrical connection. A natural gas tankless water heater installation often means upsizing the gas pipe. A propane tankless water heater installation adds tank, regulator and line considerations; see the propane tankless water heater for that path. New or extended lines fall under gas line installation.
Electric
Electric tankless water heater installation needs high-amperage circuits, not a vent. The electric tankless water heater covers the panel, wire and flow details.
A quick way to compare
- Gas: higher flow, venting required, gas line may need upgrading
- Electric: no vent, big electrical load, simpler placement
- Either: sized to flow rate and temperature rise, not tank gallons
What Determines Tankless Water Heater Installation Cost
Tankless water heater installation cost, tankless hot water heater cost, price of tankless water heater, cost of tankless hot water heaters and how much does a tankless water heater cost with installation are all shaped by the same list.
Factors that move the installed price
- Unit type, size and output
- Fuel type and whether you are switching fuel
- Gas line size, run length and any upsizing
- Electrical panel, breaker and wire upgrades
- Vent type and length, including wall or roof penetrations
- Condensate drain for condensing models
- Removal of the old tank and any patching
- Access to the wall or space where the unit will hang
- Permit, inspection and any local code requirements
- Water treatment such as filters or a softener, if recommended
- Isolation valves for future flushing
How much is a tankless water heater by itself?
How much is a tankless water heater or how much does a tankless water heater cost depends on brand, capacity and features. The unit is only part of the picture. Installation can be a large share of the total, and it varies by house.
Why quotes differ
Two quotes for tankless water heaters installed can differ because one includes vent, permit and line upgrades and the other does not. Ask each contractor to list everything. For how plumbers set fees in general, what plumbers charge and why is a useful companion.
Choosing the Right Size: GPM, Two Showers and Multi-Unit Buildings
How many GPM for tankless water heater use?
How many gpm for tankless water heater sizing depends on what you run at once. Add the flow of showers, sinks, dishwasher and washer that might overlap, then check that the unit can meet that at your coldest winter water temperature. Manufacturer flow charts state the real numbers; treat general rules with caution.
Tankless water heater for two showers
A tankless water heater for two showers usually needs a mid- to high-output unit, or two units, especially in cold climates. Low-flow showerheads help. Ask the plumber to size against simultaneous use.
Tankless water heater for apartment building
A tankless water heater for apartment building use can mean one unit per apartment or a central system. Each approach affects the gas or electrical service, maintenance and billing. Multi-unit and commercial jobs are handled as commercial plumbing and need careful engineering.
18kw and other electric ratings
An 18kw tankless water heater is a size class, not a promise of two showers. What matters is the flow at your temperature rise and whether your panel supports it.
How to choose a tankless water heater
How to choose a tankless water heater in short:
- Pick the fuel based on what your home can support.
- Size for peak flow and coldest incoming water.
- Check venting, clearances and gas or electrical needs.
- Review the warranty on the heat exchanger and parts.
- Choose an installer who does tankless work regularly.
Not sure what you need? Call and we will point you to the right help.
Call 417-261-5030The Installation Process Step by Step
A good tankless water heater installation service follows a similar sequence.
- Visit to your property to check the fuel supply, vent path, water pressure and wall space
- Written quote itemizing equipment, materials, permit and any upgrades
- Removal of the old tank if there is one
- Mounting, water connections and isolation valves
- Gas, vent or electrical work, with pressure and leak testing
- Startup, flow and temperature testing
- Walk-through of settings, error codes and flushing needs
Tankless hot water heater installation and tankless heater installation timelines
A tankless hot water heater installation takes longer than a like-for-like tank swap in most homes, since the vent, gas or electrical work has to be done. Timing depends on access and permits and is confirmed by phone.
Permits
Gas, venting and electrical work often require permits and inspection. Ask who handles them.
Alternatives That Can Cost Less Than a Whole-House Swap
A full tankless conversion is not the only way to fix a hot water complaint. Sometimes a smaller change solves the real problem.
Point of use units
If the only complaint is a long wait at a distant sink or bathroom, a point of use water heater at that location may be enough, and it avoids touching the main heater or gas line.
A better tank
If you run out of hot water mainly because the tank is small or full of sediment, a properly sized tank or a hot water recirculation setup may be cheaper than going tankless.
A partial approach
- Keep the tank for the main house and add a small unit for an addition
- Add a second unit only when a remodel adds fixtures, as in bathroom remodel plumbing
- Fix leaks and pipe insulation first; hidden losses sometimes look like a heater problem, and leak detection can help find them
How to Compare Two Tankless Quotes
Comparing quotes is easier when you turn each into the same checklist.
- Same fuel and same size class of unit?
- Is the gas line, vent, electrical, permit and haul-away in each?
- Are isolation valves and a flush kit included?
- What does the warranty cover, and who files the claim?
- What is the plan if the inspector finds a problem?
Red flags in an estimate
- No mention of the gas line or panel when the unit is large
- A single lump sum with no scope
- Pressure to decide on the spot
- No permit mentioned for gas or electrical work
- Claims about savings with no reference to your fuel prices
Availability, scheduling and final pricing are confirmed by phone, so use that call to ask these questions before anyone visits.
Need a plumber in your area? Call to confirm coverage.
Call 417-261-5030Timing the Switch: Best Moments to Go Tankless
The least disruptive time to change is when something is already open. A failed tank is one such moment, because the old unit is coming out regardless. A kitchen or bathroom remodel is another, since walls are open for piping and the vent or gas line can be routed cleanly. Selling or buying a house can also prompt it, though an upgrade done just for resale is worth pricing carefully.
Planned replacement beats emergency replacement. When the tank fails at night with water on the floor, you have little room to compare options, so a planned swap usually gives better choices and a calmer quote. If a leak is already happening, shut off the cold supply to the heater and read about emergency plumbing before deciding anything else.
Finding a Tankless Water Heater Contractor
A tankless water heater contractor or tankless installers worth hiring do this work regularly. When you search for a tankless water heater installation service, look for evidence that they size by flow rate, check gas and electrical supply, and pull permits.
Questions to ask
- How will you size the unit for my home?
- Will the quote list the gas line, vent, electrical and permit work?
- Who handles warranty claims?
- What maintenance schedule do you recommend?
- What happens if the existing vent or line cannot be reused?
Maintenance and Repair After Installation
Tankless units need periodic flushing, especially in hard water. If one develops error codes, cold spots or reduced flow, see tankless water heater repair. A sudden leak or no hot water at all can be an urgent call; emergency plumbing covers what to do while waiting. For general questions on installing any type, water heater installation is a helpful starting point.
Where You Can Get Tankless Water Heater Installation & Cost Help
Plumbing calls are taken for 21 states, 1,511 cities and 3,769 ZIP codes. Pick your state, or look at a sample city and ZIP for each state; coverage for your exact address is confirmed by phone.
- Arizona
- California
- Colorado
- Connecticut
- Florida
- Georgia
- Idaho
- Illinois
- Maine
- Massachusetts
- Michigan
- Minnesota
- Missouri
- New Hampshire
- New Jersey
- New York
- North Carolina
- Ohio
- Texas
- Virginia
- Washington
| City | ZIP codes and places |
|---|---|
| Gilbert, AZ | 85233 about 5 miles from Mesa Arts Center; about 6 miles from Wilkes University, Mesa 85234 about 5 miles from Mesa Arts Center; about 6 miles from Wilkes University, Mesa |
| Long Beach, CA | 90801 near Aquarium of the Pacific; near California State University 90802 about 1 mile from Aquarium of the Pacific; about 1.1 miles from Long Beach Museum of Art |
| Boulder, CO | 80302 near Mind and Life Institute; about 1 mile from Naropa University 80310 near Naropa University; near Folsom Field |
| Greens Farms, CT | 06436 about 7 miles from Aldrich Contemporary Art Museum; about 8 miles from Western Connecticut State University 06838 about 2.2 miles from Westport Country Playhouse; about 4.2 miles from Rafferty Stadium |
| Fort Lauderdale, FL | 33308 about 2.6 miles from Fort Lauderdale–Hollywood; about 2.6 miles from Museum of Discovery and Science 33309 near City College; about 1.1 miles from Chase Stadium |
| Atlanta, GA | 30302 near Atlanta City Hall; near Georgia State University 30303 near Georgia State University; near GSU Sports Arena |
| Fruitland, ID | 83619 about 5 miles from Ontario Municipal Airport; about 27 miles from College of Idaho |
| Palatine, IL | 60038 near Arlington Park; about 7 miles from McDonald's #1 Store Museum 60055 near Arlington Park; about 7 miles from McDonald's #1 Store Museum |
| Cape Neddick, ME | 03902 about 2.5 miles from York's Wild Kingdom; about 2.9 miles from Ogunquit Museum of American Art |
| Lawrence, MA | 01840 near Campagnone Common; near Great Stone Dam 01841 near Campagnone Common; near Great Stone Dam |
| Clinton Township, MI | 48035 about 8 miles from Jimmy John's Field; about 14 miles from Lake Saint Clair |
| Maple Plain, MN | 55359 about 7 miles from Crown College; about 7 miles from Lake Minnetonka |
| Fenton, MO | 63026 about 4.6 miles from Endangered Wolf Center; about 7 miles from Ulysses S. Grant National Historic Site 63099 about 1.4 miles from Covenant Theological Seminary; about 2.9 miles from St Louis Country Club |
| Manchester, NH | 03103 about 1.2 miles from Gill Stadium; about 1.6 miles from SNHU Arena 03104 near McIntyre Ski Area; near Currier Museum of Art |
| Newark, NJ | 07101 near Newark Velodrome; about 1.2 miles from Seton Hall University 07102 near Newark City Hall; near Prudential Center |
| Great Neck, NY | 11024 about 1.8 miles from Stepping Stones Light; about 2.6 miles from Manhasset Valley Park |
| Concord, NC | 28025 about 9 miles from Charlotte Motor Speedway; about 10 miles from CMC-NorthEast Stadium 28026 about 8 miles from Charlotte Motor Speedway; about 19 miles from Spectrum Center |
| Columbus, OH | 43201 near Billy Ireland Cartoon Library & Museum; near Wexner Center for the Arts 43202 near Jesse Owens Memorial Stadium; about 1.3 miles from Historic Crew Stadium |
| Houston, TX | 77058 near University of Houston–Clear Lake; about 1.1 miles from Lyndon B. Johnson Space Center 77062 about 1.4 miles from University of Houston–Clear Lake; about 2.1 miles from Lunar and Planetary Institute |
| Henrico, VA | 23238 about 1.5 miles from American Civil War Museum; about 1.5 miles from National Theater 23294 about 3.5 miles from E. Claiborne Robins Stadium; about 3.7 miles from University of Richmond |
| Lakewood, WA | 98439 about 1.7 miles from McChord Field; about 2.5 miles from American Lake 98496 about 2.5 miles from McChord Field; about 2.7 miles from Fort Steilacoom |
Frequently Asked Questions
How much does tankless water heater installation cost?
There is no single figure, because it depends on the unit, fuel, gas line or electrical upgrades, venting, access and permit. A plumber can give a written quote after seeing your setup. Expect installation to cost more than a like-for-like tank swap, and ask for every line item.
Is a tankless water heater worth it?
It can be if your house can support it without major upgrades, you plan to stay for years, and you like the space savings and continuous hot water. It is less compelling for very large households or homes needing expensive gas or electrical work.
How long do tankless water heaters last?
Many last longer than tank models when maintained, but the actual life depends on water quality, usage and flushing. Manufacturer warranties give guidance but are not a prediction.
Are tankless water heaters gas or electric?
Both types exist. Gas and propane models burn fuel and need a vent. Electric models need substantial electrical capacity but no vent. Which is right depends on what your home has.
Can a tankless water heater run two showers at once?
Often, if it is sized for it. Output, incoming water temperature and showerhead flow decide. Ask the plumber to size against your coldest month.
Does a tankless water heater save money?
It can reduce standby loss, so some households use less energy. Whether you save money depends on fuel prices, usage and the extra installation cost. Compare with your own bills.
What is the difference between a tank and tankless water heater?
A tank stores and reheats a volume of hot water, while a tankless unit heats water on demand. Tankless saves space and avoids standby loss but requires more from your gas or electrical supply.
Do I need a permit for tankless water heater installation?
Often yes, especially for gas, venting and electrical work. The plumber usually handles it, but ask so it is clear who is responsible.
Can I install a tankless water heater myself?
Gas and high-voltage work are not DIY territory. Mistakes can cause gas leaks, carbon monoxide exposure or electrical hazards. Hire a plumber.
What size tankless water heater do I need?
Size by peak flow and the temperature rise from your coldest incoming water. A plumber can calculate this and check that your gas line or panel can support the unit.
What can make my quote higher than someone else's?
Differences in scope. One quote may include the vent, permit, gas line upsizing or electrical work, while another leaves them out. Ask for itemized quotes so you compare like with like.
Ready to talk to a plumber? Call 417-261-5030.
Call 417-261-5030