Water Heater Repair St. Louis: $60 to $650 + Permits (2026)

St. Louis rows are Angi's city figures; national rows are marked.

Do this now: water heater leaking or out in St. Louis

1. Smell gas? Leave the house and call 911 or Spire from outside. Do not flip switches or look for the leak. The Kansas Corporation Commission's gas safety page says not to use phones or switches near the smell.
2. Leaking: close the cold water valve on top of the tank. On an electric heater, switch off its breaker.
3. Water dripping from the relief valve pipe: do not cap or plug it. This Old House says plugging the discharge pipe stops the valve from working.
4. Water on the floor near outlets: use the breaker only from a dry spot (Red Cross).
5. No hot water but no leak: check the breaker on an electric heater or whether the pilot is lit on a gas one. HomeAdvisor says drafts can blow a pilot out.

Is it urgent? When a water heater cannot wait

A water heater is urgent when the tank itself is leaking, when you smell gas, or when the relief valve keeps discharging. HomeGuide says a leak from the bottom of the tank usually means the tank is damaged and must be replaced, while leaks at fittings, the drain valve or the relief valve may be fixable. No hot water in a St. Louis winter, with 84.9 freezing nights a year at Lambert (NOAA), is worth a same-day call; Angi puts an emergency water heater repair in St. Louis at $210 to $905. Rumbling or lukewarm water can wait for a weekday. More symptoms on water heater repair.

St. Louis water hardness and your water heater

City of St. Louis water averages 129 ppm of total hardness, with a range of 80 to 206 ppm, the Water Division's 2025 Consumer Confidence Report shows. The water comes from the Missouri and Mississippi rivers through the Howard Bend and Chain of Rocks plants. Hard water leaves sediment in a tank, and HomeGuide links popping and rumbling noises to sediment. A flush costs $75 to $250 nationally, HomeGuide says. St. Louis County homes are served by different utilities, so check your own water report there.

Do you need a permit to replace a water heater in St. Louis?

Ask before you sign. The City issues plumbing permits only to licensed plumbing contractors certified by the City, with a $30 application fee plus a fee schedule. Its plumbing permit page names fixtures, sewer laterals, stacks and water supply lines but does not name water heaters, so have the plumber confirm in writing whether your swap needs a permit. A gas heater also involves the gas piping and venting. The Plumbers and Drainlayers Board licenses plumbers; there is no online search, so call the Building Division at (314) 622-3313.

Repair or replace a St. Louis water heater?

Replace a tank that is leaking from the body or is past its life: the Department of Energy says storage water heaters last 10 to 15 years and tankless about 20. HomeGuide suggests replacing a tank over 10 years old or when the repair is more than half the price of a new one. HomeAdvisor puts a replacement at $882 to $1,826 nationally. With St. Louis's median house built in 1939 or earlier, check the venting and the gas line too when a new heater goes in. Prices for tank, tankless and heat pump units are on water heater replacement cost.

Set it to 120 F

CPSC urges setting water heaters to 120 F. Most adults get third-degree burns from 150 F water in about two seconds, and at 140 F in about six, CPSC says. This Old House says manufacturers recommend testing the temperature and pressure relief valve every six months to a year.

Local rules, programs and climate for St. Louis, from the official city, utility, state, Census and NOAA pages listed under Sources.

Questions to ask a St. Louis water heater company

1. Are you certified by the City to pull plumbing permits, and does this job need one?
2. What is the diagnostic or trip fee, and is it credited to the repair?
3. Is the price for the part alone or installed?
4. How old is my tank, and is a repair worth it at that age?
5. Can I see proof of insurance and a written price before work starts?

More St. Louis plumbing guides

All plumbing, sewer laterals and permits: plumber in St. Louis. After hours: emergency plumber in St. Louis. Water on the basement floor: water damage restoration in St. Louis. Compare water heater repair in Kansas City and water heater repair in Chicago. Going tankless? See tankless water heater installation. Calls go to an independent company that serves your area and takes this kind of job (how calls work).