HomeCostGuideTankless Water Heater Cost
Written and reviewed by the HomeCostGuide editorial team
Quick answer
$3k–$4kinstalled, gas or electric tankless
A tankless water heater typically costs $2,800–$4,200 installed — roughly double a standard tank replacement. Most of that premium is installation labor rather than equipment alone: gas tankless units often need upgraded venting and sometimes a larger gas line, while electric tankless units can require an electrical service upgrade to handle their higher amperage draw. In exchange, tankless units eliminate standby heat loss, take up a fraction of the space of a tank, and typically last 15–20 years versus 8–12 years for a standard tank — a longer lifespan that partly offsets the higher upfront cost over time.
How this differs from a full water heater replacement
This page covers tankless-specific cost and installation factors. For a full side-by-side on upfront cost, efficiency, and which one fits your household better, see our tankless vs. tank water heater comparison instead of this page.
What's typically included
Included at this scope
- Tankless unit (gas or electric)
- Venting upgrades for gas units
- Electrical service assessment for electric units
- Removal of the old tank
Not included (see the full guide)
- Standard tank replacement (see the full water heater replacement guide)
- Side-by-side comparison against tank units (see our tankless vs. tank comparison)
- Whole-house repiping
What affects the price
- Venting requirements
- Gas tankless units often need dedicated venting different from a standard tank, which is the single biggest driver of installation cost above the equipment price.
- Electrical or gas line upgrades
- Electric tankless units draw significantly more amperage than a tank; gas units sometimes need a larger gas line to deliver enough flow for the unit's rating.
- Correct sizing (GPM)
- Tankless units are rated by maximum flow rate — undersizing for your household's peak simultaneous demand is a common and costly mistake to avoid.
Frequently asked questions
Is tankless worth double the cost of a tank replacement?+
It depends on household size and how long you'll stay in the home — tankless units last longer (15–20 years vs. 8–12) and lower standby energy loss, but the payback period varies widely. See our tankless vs. tank comparison for the full tradeoffs.
Do I need to upgrade my gas line or electrical panel for tankless?+
Often, yes — this is the main reason tankless installation costs more than the unit price alone. A plumber or electrician can confirm what your specific home needs during a quote.
Full guide
Cost ranges on this page are a narrower cut of our full Water Heater Replacement Cost guide, which covers labor share, regional adjustment, resale value, financing, and sourcing in full. See it for the complete breakdown this page’s figures are drawn from.