Cost guide
What a water heater replacement costs in Florissant
This is the plumbing purchase most households make with no warning and no time to research. Here are real ranges for the Florissant area, including the things a 1960s basement tends to add to the bill.
- Standard tank: $1,500 – $2,800 installed
- Tankless: $4,000 – $7,000 installed
- Includes removal and haul-away
- Updated for 2026 St. Louis County pricing
Typical ranges
What it runs in the Florissant area
Planning ranges for Florissant and North County, inclusive of labor and mid-grade materials.
40–50 gal electric tank
Like-for-like swap in an accessible basement. Includes new connections, drain pan and haul-away.
$1,500 – $2,400
40–50 gal gas tank
Same swap with venting checked and corrected. Gas runs cheaper monthly in this market.
$1,700 – $2,800
75 gal or high-recovery tank
Larger households or long fixture runs. Heavier unit, sometimes an electrical or gas line upgrade.
$2,600 – $4,200
Tankless (gas)
New venting, gas line sizing and often a condensate drain. In a sixty-year-old house the gas line is frequently the deciding cost.
$4,000 – $7,000
Older-home adders
Undersized gas line, venting that no longer meets code, no drain pan, a missing expansion tank, or a seized shutoff valve.
Add $400 – $1,800
Ranges are estimates for planning only and are not a quote or an offer. Your firm price is confirmed on site.
Detail
What an older Florissant house adds
Gas line sizing
A tankless unit demands far more gas than a tank. A 1963 gas line is often undersized for it, and upsizing is real labor.
Venting
Houses this age have had two or three heaters swapped in. Venting that was acceptable for the first one is not always acceptable now.
No drain pan
Common in older installs. In a finished lower level a pan and a place for it to drain is not optional, it is the difference between a drip and a claim.
Seized shutoff
The cold inlet valve frequently has not moved in a decade. If it will not close, it gets replaced as part of the job.
Expansion tank
Required on many closed systems. Modest part, but it belongs in the quote rather than appearing later.
Access
A heater in a tight utility closet under a stairwell costs more to remove and set than one standing in an open basement.
The honest answer
Repair or replace?
The line we actually use, rather than the one that sells the most units.
Under about eight years old with a failed thermostat, element, thermocouple or T&P valve, repair it — those are parts, not a new appliance. Ten years or more, rusty hot water, or any leak at the tank seam, replace it, because a leaking tank cannot be repaired. Between eight and ten with a repairable fault is a genuine judgment call, and we will give you the repair number and the replacement number side by side rather than deciding for you. One thing worth knowing: if your heater sits in a finished lower level and it is past ten years, replacing on your schedule costs the same as replacing on its schedule, minus the flooring.
Common questions
What homeowners ask us
How much does it cost to replace a water heater in Florissant?
Most standard tank replacements run $1,500 to $2,800 installed, including removal and haul-away. Tankless runs $4,000 to $7,000, largely because of venting and gas line work in older homes.
Why is tankless more expensive here than the unit price suggests?
In a house built in the 1960s the existing gas line is often undersized for a tankless unit, and new venting is usually required. That labor, not the appliance, is the bulk of the difference.
Is it cheaper to repair or replace?
Under eight years with a repairable fault, repair. Ten-plus years, rusty hot water, or a leak at the seam means replace — a leaking tank cannot be fixed.
Do I need a drain pan?
If the heater is anywhere near finished space, yes, and it needs somewhere to drain. Plenty of older installs have neither.
How long does the install take?
A straightforward tank swap is a few hours. Tankless is typically most of a day, longer if the gas line needs upsizing.
Free estimate
Get a real number for your home
Guides are for planning. For an actual price, tell us what you have and we will give you a firm number.
Related: water heater service, emergency plumber, galvanized pipe replacement, signs you need a plumber, leak detection
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