Traditional tank water heaters remain the most popular choice for St. Louis homes — reliable, affordable, and straightforward to install and maintain. STL Plumbing Pros installs gas and electric tank water heaters in 40, 50, and 75-gallon sizes. We properly size the unit to your household, handle all connections, and remove your old water heater. Same-day installation available for standard replacements.
When to Replace Your Water Heater
Unit is 8–12 years old — approaching or past expected lifespan.
Rust-colored hot water — indicates tank corrosion that can't be repaired.
Water pooling around the base — tank is leaking and failure is imminent.
Not enough hot water — sediment buildup or failing heating elements.
Strange noises — popping, rumbling, or banging from sediment accumulation.
Our Installation Process
Assessment & Sizing
We evaluate your current setup, recommend the right size based on household demand, and provide a complete quote including all connections, venting, and code requirements.
Remove & Install
Disconnect and remove the old unit, position the new water heater, connect gas/electric, water supply and distribution, install expansion tank if required, and ensure proper venting.
Test & Commission
Fill the tank, check all connections for leaks, verify gas connections with electronic leak detection, test hot water delivery, and set the thermostat to the recommended 120°F.
Water Heater Installation Pricing
| Service | Price | Details |
|---|---|---|
| 40-gallon gas tank water heater (supply & install) | $1,200–$2,000 | Standard residential size for 2–3 person households. |
| 50-gallon gas tank water heater (supply & install) | $1,400–$2,400 | Recommended for 3–5 person households. |
| Electric tank water heater (40–50 gal) | $1,000–$1,800 | Lower upfront cost, no gas line or venting required. |
| Expansion tank installation | $150–$300 | Required by code in St. Louis for closed-loop systems. |
| Old unit removal and disposal | Included | We remove and properly dispose of the old water heater. |
Why Choose STL Plumbing Pros?
⚡
Same-Day Installation
We stock common sizes and can complete most standard replacements the same day you call.
🗑️
Old Unit Removed
We remove and properly dispose of your old water heater — no rusty tank sitting in your basement waiting for disposal.
📋
Code Compliant
Every installation meets current St. Louis building codes including expansion tanks, proper venting, and seismic strapping where required.
What Our Customers Say
"Water heater failed on a Saturday morning. They came out same day, had a new 50-gallon installed by afternoon. Hot showers that evening. Can't beat that."
"Straightforward replacement — old one removed, new one installed, everything cleaned up. Fair price, no surprises."
"Appreciated the honest sizing recommendation. They said our 40-gallon was fine for our household instead of upselling us to a 50."