Gas tank water heater replacement cost in St. Louis, MO
Installed, 50 gallon, standard vent
A typical gas water heater (50 gallon, standard vent) costs about $2,100 installed in the St. Louis area, 5% above the national figure, because plumbers here earn a median $37 an hour against $31 nationally.
Prices by size in St. Louis
| Size | Low | Typical | High | National typical |
|---|---|---|---|---|
| 40 gallon, standard vent | $1,700 | $2,000 | $2,550 | $1,900 |
| 50 gallon, standard vent | $1,750 | $2,100 | $2,750 | $2,000 |
| 75 gallon, standard vent | $2,500 | $2,900 | $3,500 | $2,800 |
| 40 gallon, power vent | $2,500 | $2,850 | $3,350 | $2,750 |
| 50 gallon, power vent | $2,700 | $2,950 | $3,600 | $2,850 |
Local labor: what plumbers earn here
| Hourly wage | St. Louis metro | United States |
|---|---|---|
| 25th percentile | $28 | $24 |
| Median | $37 | $31 |
| 75th percentile | $50 | $41 |
The St. Louis market
The City of St. Louis Building Division issues plumbing permits only to licensed plumbing contractors certified by the city, and mechanical permits only to city-certified licensed mechanical contractors. No homeowner route is stated. The plumbing fee schedule prices a water heater as a fixture at $10, plus a $30 application fee. For homes, mechanical permits carry a $25 application fee plus $40 for each furnace, condensing unit or combination furnace and condensing unit. Heat pumps are not named. After approval you print the permit and schedule inspections through the STL City Permits dashboard. EIA found furnaces are main heat in 76% of Missouri homes and central air serves 83%. St. Louis County, a separate government from the city, has its own permit office, and so do the Illinois counties in the metro.
Missouri homes split almost evenly on water heating, 50% gas and 47% electric in EIA's survey. Many city homes are older brick houses with basement heaters venting into a chimney. A new tank can draft poorly in an old, oversized flue, so ask the plumber to check the chimney and liner. Ask whether the vent connector and gas shutoff will be replaced, and whether haul-away is included.
Permits in St. Louis
| Permit for this job | Yes (inferred: plumbing permit fee schedule prices 'water heater' as a fixture; permit pages do not name water heaters) (source) |
|---|---|
| Fee | Plumbing: $30 application fee + $10 per fixture (water heater listed). Mechanical (R1-R3 residential): $25 application fee + $40 per furnace, $40 per condensing unit, or $40 per combination furnace/condensing unit. |
| Who can pull it | City-licensed contractor only (City plumbing contractor or mechanical contractor license); homeowner route not stated |
| Inspection | Yes (scheduled through STL City Permits dashboard after approval) |
Rebates in Missouri
HEAR: announced, not open yet. HOMES: announced, not open yet. Source: Missouri DNR Division of Energy, checked October 13, 2026.
What these programs cover, and other states
Other systems in St. Louis
- Gas tankless water heater
- Gas furnace
- Central air conditioner
- Heat pump (ducted, outdoor unit + air handler)
Gas tank water heater cost in other metros
Sources
- City of St. Louis: Mechanical permits
- City of St. Louis: Plumbing permits
- City of St. Louis: Plumbing permit fees
- City of St. Louis: Mechanical permit fees
- Missouri DNR: IRA home energy rebates
- EIA, 2020 RECS: Highlights for space heating in U.S. homes by state
- EIA, 2020 RECS: Highlights for water heating in U.S. homes by state
- EIA, 2020 RECS: Highlights for air conditioning in U.S. homes by state
- BLS OEWS May 2025, St. Louis, MO-IL (47-2152 plumbers)
- DOE Consumer Water Heaters Final Rule TSD (Apr 2024), Table 8.2.7 (2022$); labor share from App. 8D (3.75 h + trip, $420 of $791)