Gas Tankless Water Heater Installation Cost in 2026
$2,100–$5,600
Natural gas installed
$2,500–$6,000+
Propane installed
$700–$1,995
Unit cost range
$600–$1,850
Labor cost
Complete Gas Tankless Cost Breakdown
| Cost Component | Range | Notes |
|---|---|---|
| Unit (whole-house gas) | $700–$1,995 | Rinnai/Navien top end; Rheem/Bosch lower end |
| Labor, standard install | $600–$1,200 | Direct swap, compatible venting, no gas work |
| Labor, with venting work | $800–$1,500 | New vent run through wall/ceiling |
| Venting materials | $200–$600 | Direct, power, or concentric vent kit + pipe |
| Gas line upgrade (if needed) | $300–$800 | Upsizing existing supply line; not always required |
| Condensate drain (condensing) | $75–$200 | Only for high-efficiency condensing units |
| Permit | $50–$250 | Required in most US jurisdictions for gas work |
| Old unit removal/disposal | $50–$150 | Often included in labor quote |
Natural Gas vs Propane: Cost & Considerations
Natural Gas
$2,100–$5,600installed
Running cost: $25–$60/month
Pros
- Lower operating cost than propane
- Consistent utility pricing
- Most installer experience
Cons
- Not available in rural areas
- Gas line upgrade often needed
- Cannot convert to propane easily
Propane
$2,500–$6,200installed
Running cost: $35–$90/month
Pros
- Available anywhere (rural areas)
- Same tank unit, different orifice
- Higher BTU per unit than NG
Cons
- Higher operating cost than NG
- Tank rent/ownership cost
- Price volatility
Propane operating cost note: Propane typically costs 2–3× more per BTU than natural gas. If you have access to natural gas, the operating cost savings over 10 years often justify the modest extra installation cost of running a gas line vs staying on propane. See savings guide →
Gas Tankless Water Heater Cost by Brand
| Brand | Unit Cost | BTU Range | Installed Total | Warranty (HX) | Best For |
|---|---|---|---|---|---|
| Rinnai | $500–$1,700 | 120K–199K | $2,500–$4,500 | 12 years | Reliability-first buyers |
| Navien | $1,075–$1,535 | 150K–199.9K | $3,900–$7,200 | 15 years | Highest efficiency |
| Rheem | $500–$1,200 | 150K–199K | $1,800–$4,000 | 12 years | Budget-conscious; HD/Lowe's buyers |
| Noritz | $600–$1,400 | 120K–199.9K | $2,500–$4,800 | 12 years | Rinnai alternative; commercial use |
| Bosch | $500–$1,100 | 120K–167K | $2,200–$4,000 | 10 years | Non-condensing direct swaps |
See full brand comparison with reliability ratings and where to buy →
Labor Cost Detail: What You're Paying For
Labor is the most variable cost in a gas tankless installation. A standard direct-swap job takes 3–5 hours; complex installations with new gas and vent runs can take 2 full days. Here's what a comprehensive quote should include:
Standard install scope
- Remove old unit and dispose
- Mount new unit
- Connect existing water lines
- Connect to existing gas line
- Commission and test unit
- Instruct homeowner on operation
Potential extra charges
- New vent run ($200–$600)
- Gas line upsizing ($300–$800)
- Condensate drain ($75–$200)
- New water lines ($100–$300)
- Permit fees ($50–$250)
- Emergency/weekend rate (+25–50%)
Contractor pricing tip: Labor rates for the identical job vary 40–60% between contractors. Always get 3 quotes specifying the exact model number and full scope of work. Compare quotes line-by-line, a low total quote may exclude venting or permits that others include.
Frequently Asked Questions
Condensing units extract heat from exhaust gases before venting, achieving 90–98% efficiency (EF/UEF 0.90–0.98). They require a condensate drain to remove acidic water produced during the process. Non-condensing units are simpler to install (no condensate drain, higher-temp exhaust) but less efficient at 80–85%. Condensing units cost $100–$400 more to buy and $150–$300 more to install, but recover the difference through lower operating costs within 2–4 years.