Commercial Water Heater Sizing Calculator — St. Louis
Estimate peak hot water demand, storage and burner input for your building. We install and replace gas and electric commercial water heaters across the St. Louis metro.
Recommended Sizing
Peak hour demand
20 gal/hr
Storage tank
1 × 50 gal
Gas or electric
Burner input
16k BTU/hr
High-efficiency condensing
Tankless option
1 × 199k
Racked units
Installed cost range
$3,900 – $7,900
Storing above 120°F? A thermostatic mixing valve is required to prevent scalding at fixtures.
Conceptual estimate only — not a bid or quote. Actual cost depends on site conditions, access, code requirements and material pricing. Legacy Plumbing will confirm scope and pricing in writing.
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