Gas tankless water heater replacement cost in Louisville, KY
Installed, About 180,000–199,000 BTU (2–3+ bathrooms)
A typical tankless water heater (About 180,000–199,000 BTU (2–3+ bathrooms)) costs about $2,900 installed in the Louisville area, 4% above the national figure, because plumbers here earn a median $36 an hour against $31 nationally.
Prices by size in Louisville
| Size | Low | Typical | High | National typical |
|---|---|---|---|---|
| About 150,000 BTU (1–2 bathrooms) | $2,050 | $2,750 | $3,550 | $2,650 |
| About 180,000–199,000 BTU (2–3+ bathrooms) | $2,600 | $2,900 | $3,900 | $2,800 |
Local labor: what plumbers earn here
| Hourly wage | Louisville metro | United States |
|---|---|---|
| 25th percentile | $25 | $24 |
| Median | $36 | $31 |
| 75th percentile | $43 | $41 |
The Louisville market
Louisville Metro's Construction Review office requires a permit to install, repair or replace any mechanical system and issues a "Residential HVAC Replacement" permit. For 1-2 family homes the fee is $105 for the first system and $50 for each additional one, with three inspections included and extra inspections at $50. A Kentucky HVAC Master or Journeyman must be on site for the entire installation or repair. Permits go to licensed HVAC contractors holding a Kentucky HVAC Master license and a Metro HVAC Contractor's License, or to the owner in person with photo ID and recorded property documents. Water heater permit rules were not found, so confirm. DOE puts Jefferson County in mixed-humid zone 4A; EIA's 2020 survey found 49% of Kentucky homes heat with electricity, 43% with gas, and 84% have central air.
With only a third of Kentucky water heaters on gas, a gas tankless unit fits Louisville homes that already have adequate gas service. Converting usually means new venting and a gas line check, both licensed-plumber tasks. Ask the plumber to name the permit on the quote. Zone 4A winters cool the incoming water, so ask what flow rate the unit holds in January and whether isolation valves are included for descaling.
Permits in Louisville
| Permit for this job | Not stated on the city pages we checked (source) |
|---|---|
| Fee | $105 for the first system, $50 for each additional system (1 & 2 family, new or replacement); each HVAC permit includes 3 inspections; additional inspections $50 (since Nov 1, 2022). Water heater fee: none found. |
| Who can pull it | HVAC: licensed HVAC contractor (KY HVAC Master + Metro HVAC Contractor's License) or the property owner in person with ID and recorded property documentation |
| Inspection | Yes |
Rebates in Kentucky
HEAR: announced, not open yet. HOMES: announced, not open yet. Source: Kentucky Office of Energy Policy (Energy and Environment Cabinet), checked October 13, 2026.
What these programs cover, and other states
Other systems in Louisville
- Gas tank water heater
- Gas furnace
- Central air conditioner
- Heat pump (ducted, outdoor unit + air handler)
Gas tankless water heater cost in other metros
Sources
- Louisville, KY permit source (water heater permit)
- Louisville, KY permit source (hvac permit)
- Louisville, KY permit source: 1&2 family HVAC $105 first system, $50 each additional; 3 inspections
- DOE Building America: Guide to Determining Climate Regions by County
- Kentucky Home Energy Rebates
- EIA RECS 2020: Highlights for space heating fuel in U.S. homes by state
- EIA RECS 2020: Highlights for space heating in U.S. homes by state
- EIA RECS 2020: Highlights for air conditioning in U.S. homes by state
- EIA RECS 2020: Highlights for water heating in U.S. homes by state
- BLS OEWS May 2025, Louisville/Jefferson County, KY-IN (47-2152 plumbers)
- DOE Gas-fired Instantaneous Water Heaters Final Rule TSD (Dec 2024), Table 8.2.6 (2023$)