Commercial Water Heater Service & Replacement in St. Louis, MO
No hot water closes restaurants, clinics, and locker rooms. Legacy Plumbing services and replaces high-volume tank, tankless, and recirculating water heating systems across the St. Louis metro with minimal downtime.
Request Water Heater Service
Tell us scope, schedule, and site address. We reply within one business day.
Water Heating Systems We Handle
Sized to real demand, vented to code, and installed so the next service call is easy.
High-Volume Tank Heaters
Gas and electric commercial tanks, storage tanks, and multi-unit banks sized to peak demand.
Tankless & Condensing Systems
Rack-mounted condensing tankless installs with cascade controls, proper venting, and condensate neutralization.
Recirculation Systems
Pumps, aquastats, balancing valves, and timers so hot water arrives fast without wasting energy.
Mixing & Safety Valves
Thermostatic mixing valves, T&P relief, expansion tanks, and scald protection to code.
Emergency Replacement
Same-week swap-outs with temporary hot water arranged where the operation can't wait.
Scale & Efficiency Service
Descaling, anode replacement, and combustion tuning that extend life and cut gas spend.
How a Replacement Runs
Load Sizing
We calculate real peak demand instead of matching the nameplate on a unit that was undersized to begin with.
Equipment & Options
Tank vs. tankless comparison with install cost, gas usage, footprint, and expected life for each.
Rig & Install
Old unit removed, new equipment rigged in, gas, water, venting, and controls tied in and permitted.
Start-Up & Documentation
Combustion testing, temperature verification, and an O&M package with warranty registration.
Commercial Water Heater FAQ
Should we go tankless?
Tankless wins on footprint, efficiency, and continuous demand; tanks win on high simultaneous draw and lower up-front cost. We size both and show you the numbers before you decide.
How fast can you replace a failed commercial heater?
Most common commercial sizes are available locally and we can typically swap within days — with temporary hot water arranged when the operation can't pause.
Do you service equipment you didn't install?
Yes. We service all major commercial brands and can add the unit to a scheduled maintenance plan.
Commercial Water Heaters Across the St. Louis Metro
Restaurants on The Hill, dental groups in Kirkwood, schools in Francis Howell and Fort Zumwalt, and locker rooms in Chesterfield and Wentzville all live and die on hot water availability.
We stock and install commercial water heating across the St. Louis metro, with scheduled service from 7am–3:30pm daily when a unit goes down.
Don't see your city below? We work the entire metro and a 2-hour radius from O'Fallon, MO. View full service area →
St. Charles County
Warren County
Water Heater Failing at Your Facility?
Send the model and building type — we'll size the replacement and quote it.