100 Gallon Tank, Installed
100 Gallon Water Heater Installation Cost (2026)
DOE's average installed cost for an electric water heater from 55 to 120 gallons, a class that already has to meet a heat-pump-level standard, is $2,019 (2022 dollars, 89 FR 37778, 6 May 2024). The largest Rheem heat pump Home Depot listed on 13 Nov 2026 was 80 gallons at $2,798, tank only.
Page updated 15 November 2026
Installed: product plus labour
DOE average installed cost
Average total installed cost per tank in the DOE consumer water heater final rule (89 FR 37778, 6 May 2024), in 2022 dollars. These are national averages across homes, not a quote.
| DOE product class | Current standard | Level required from 6 May 2029 |
|---|---|---|
| Electric storage, over 55 to 120 galHeat-pump efficiency already required; covers 100 gallon electric | $2,019 | $2,028 |
Tank only, on the shelf
Home Depot price, 13 Nov 2026
Regular (non-sale) price read on homedepot.com with store Ellsworth, ME 04605. No installation, permit or haul-away.
- Rheem ProTerra 80 gal heat pumpXE80T10HS45U1$2,798
- Rheem Performance 50 gal tall natural gas, 38,000 BTUXG50T06EC38U1$749
We have not recorded a 100 gallon tank price; the 50 gallon gas tank is shown for the two-tank option. DOE's rule did not cost gas tanks above 55 gallons.
What sits between the shelf price and a 100 gallon install bill is labour, fittings, venting or wiring, the permit and haul-away of the old tank. No national price list for that work is published (Home Depot's installation page gives no price), so get it as a written quote. For scale, the median US plumber earned $30.67 an hour in May 2025 (BLS); that is pay, not the rate a firm bills, which also covers the van, insurance, overhead and profit.
Right Use Cases
Who Needs 100 Gallons
A 100 gallon tank is for very large households, homes with several bathrooms in use at once, or large soaking tubs and body-spray showers. Gas tanks at this size are often sold as light-commercial units, which can change the permit and venting your local code requires; ask the building department before you buy.
For most homes the realistic choices are a 75 gallon tank, a whole-house tankless unit (tankless gas installation cost), or two 50 gallon tanks piped together.
Two Tanks
Two 50 Gallon Tanks Instead of One 100
Two 50 gallon tanks piped in parallel give the same storage and keep hot water running if one tank fails. Each tank is a standard residential unit; Home Depot listed the Rheem Performance 50 gallon gas tank at $749 on 13 Nov 2026. The trade-offs are floor space, a second set of connections and venting, and two tanks to maintain.
Each 50 gallon tank sits in DOE's 20 to 55 gallon class, so the 50 gallon page gives the DOE installed-cost averages that apply to it.
Regulatory Context
A 100 Gallon Electric Tank Means a Heat Pump
DOE's standards for electric storage water heaters above 55 gallons can only be met with heat-pump technology, as the DOE consumer water heater final rule records. The exception is grid-enabled resistance tanks above 75 gallons, sold for utility load-control programs. From 6 May 2029 the class standard rises slightly: DOE's average installed cost moves from $2,019 to $2,028 (2022 dollars).
The federal Section 25C tax credit ended for property placed in service after December 31, 2025, so no federal credit applies to a 2026 install. State and utility heat-pump rebates still run in some areas; check your utility before you buy.
FAQ
100 Gallon Water Heater Cost Questions
How much does a 100 gallon water heater cost installed?
DOE's average installed cost for an electric water heater from 55 to 120 gallons, a class that already has to meet a heat-pump-level standard, is $2,019 in 2022 dollars (DOE consumer water heater final rule, 89 FR 37778, 6 May 2024). The largest Rheem heat pump Home Depot listed on 13 Nov 2026 was the Rheem ProTerra 80 gal heat pump at $2,798, tank only. DOE's figures are national averages across homes; a written quote for your home is the only exact number.
Is a 100 gallon water heater residential or commercial?
Both exist. Electric 100 gallon tanks fall in DOE's residential class of 55 to 120 gallons, which requires heat-pump efficiency. Many gas tanks of this size are light-commercial units; your building department decides which permit applies.
Does the DOE rule allow 100 gallon resistance electric tanks?
Only grid-enabled models above 75 gallons, sold for utility load-control programs. Other electric storage tanks above 55 gallons need heat-pump efficiency.
Should I install a 100 gallon tank or two 50 gallon tanks?
Two tanks give the same storage, keep hot water running if one fails, and use standard parts. One tank takes less floor space and one set of connections. Get both quoted.
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