Tankless water heater installation costs $2,500–$5,000 in the US, including the unit (~$1,000–$2,500) and labor. Whole-home gas units run highest; point-of-use electric units are cheapest. They last 20+ years (vs 10–12 for tank models) and reduce water-heating energy use by 24–34%. The 25C tax credit covers 30% up to $600. In Poland expect PLN 3,500–10,000; in the Netherlands €1,500–€4,500.
Tankless water heater cost by type
| Type | Equipment (USD) | Installed (USD) |
|---|---|---|
| Gas, whole-home (180k–199k BTU) | $1,200–$2,500 | $2,800–$5,500 |
| Electric, whole-home (27 kW) | $700–$1,500 | $2,000–$4,000 |
| Point-of-use electric | $200–$500 | $400–$1,000 |
| Condensing gas (high efficiency) | $1,800–$3,500 | $3,500–$6,500 |
Cost in the United States
Most US homes pay $3,000–$4,500 for a gas whole-home tankless. Rinnai, Navien, and Rheem dominate. Pay attention to flow-rate sizing — undersized units can't run two showers at once. Federal 25C credit (30% up to $600) plus utility rebates ($150–$500) make payback faster.
What affects the cost?
- Fuel switching — going gas-to-electric or vice versa adds $500–$2,500
- Venting — gas units need stainless flue or PVC for condensing models
- Gas line upgrade — many tankless units need 3/4" gas line (vs 1/2" for tanks)
- Electrical upgrade — whole-home electric tankless may need a 200A panel
- Water hardness — hard-water areas should add a softener or annual descale ($150–$300)
How to save
- Right-size, don't oversize — bigger tankless = bigger gas line + more $
- Time with tank replacement — labor overlap saves $300–$800
- Annual descale — extends life and protects warranty
- Stack 25C credit + utility rebate — most homeowners miss the utility rebate
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