A new water heater is not tax deductible for most homeowners in 2026, and the federal energy credit that used to cover high-efficiency and heat pump units expired at the end of 2025. What you can do instead depends on how the property is used: add the cost to your home’s basis if it’s your residence, or depreciate it over time if it’s a rental or commercial building. A narrow medical-necessity deduction exists but rarely produces a meaningful write-off.
The Federal Energy Credit Ended December 31, 2025
Through 2025, the Energy Efficient Home Improvement Credit paid 30 percent of the cost of a qualifying water heater, capped at $600 for high-efficiency gas or propane units and $2,000 for heat pump models. A separate Residential Clean Energy Credit covered 30 percent of a solar water heating system with no dollar cap.
The One Big Beautiful Bill Act, signed July 4, 2025, repealed both. The Section 25C credit does not apply to property placed in service after December 31, 2025, and the Section 25D credit does not apply to expenditures made after that date.1Internal Revenue Service. One, Big, Beautiful Bill Provisions Paying in 2025 doesn’t rescue an installation finished in 2026; the solar credit only applies if the system was placed in service by December 31, 2025.2Internal Revenue Service. FAQs for Modification of Sections 25C, 25D, 25E, 30C, 30D, 45L, 45W, and 179D Under Public Law 119-21
If you installed a qualifying unit before the cutoff and haven’t filed your 2025 return yet, you can still claim the credit on IRS Form 5695. Subtract any manufacturer rebates or utility subsidies from the cost before applying the 30 percent, and hold onto the manufacturer’s certification statement along with your receipts.3Internal Revenue Service. Energy Efficient Home Improvement Credit
What Homeowners Get Instead: A Higher Cost Basis
Replacing a water heater in your own home in 2026 produces no credit and no immediate deduction. It is a capital improvement that raises your home’s adjusted cost basis, which the IRS uses to calculate your profit when you sell.
If you bought your home for $300,000 and spend $3,000 on a new water heater, your basis becomes $303,000. Selling later for $550,000 leaves you with a $247,000 gain instead of $250,000. For most homeowners the capital gains exclusion absorbs the whole thing anyway: up to $250,000 for single filers and $500,000 for married couples filing jointly.4Office of the Law Revision Counsel. 26 USC 121 – Exclusion of Gain From Sale of Principal Residence Where the basis adjustment matters is when your gain exceeds those thresholds, which happens more often than people expect after long ownership or in high-appreciation markets.
To claim the higher basis at sale, you need the original receipt and proof the work was done. Keep those records for the entire time you own the home, plus at least three years after filing the return for the year of sale.5Internal Revenue Service. How Long Should I Keep Records A scanned copy in the cloud is fine.
Rental and Business Property: Depreciation
A water heater in a rental unit or commercial building is a business asset. Residential energy credits never applied to rental property, but you recover the cost through depreciation deductions against your rental or business income.
Because the water heater becomes part of the building’s plumbing, the IRS treats it as a structural component. In a residential rental, that means 27.5-year depreciation under MACRS.6Internal Revenue Service. Publication 527 (2025), Residential Rental Property A $2,000 replacement generates roughly $73 in annual deductions. Report it on Schedule E along with the rest of your rental income and expenses. In a commercial building, the recovery period stretches to 39 years.7Internal Revenue Service. Publication 946 (2025), How To Depreciate Property
Why Section 179 and Bonus Depreciation Usually Don’t Help
Landlords often ask about deducting the whole cost in year one. Two provisions can do that in theory. Section 179 allows immediate expensing of certain qualifying property, with a 2026 limit of $1,250,000, and Congress made HVAC property eligible. Whether a water heater qualifies as HVAC depends on classification: a unit that’s part of the building’s heating system has a better argument than a standalone tank that only supplies domestic hot water. Talk to a tax professional before filing on that basis.
Bonus depreciation was restored to 100 percent by the One Big Beautiful Bill Act for qualified property acquired after January 19, 2025, but it only applies to assets with a recovery period of 20 years or less.8Internal Revenue Service. Treasury, IRS Issue Guidance on the Additional First Year Depreciation Deduction Amended as Part of the One Big Beautiful Bill A water heater sitting inside a 27.5-year or 39-year structural class doesn’t clear that bar, so bonus depreciation generally won’t apply to a standard replacement.
A Narrow Medical Deduction
In limited situations, a water heater installation can count as a deductible medical expense. The unit has to be medically necessary for a specific condition, and a physician has to recommend it. A system delivering precisely controlled temperatures for someone with a chronic skin disorder or severe immune deficiency is the kind of case that fits.
You don’t deduct the full cost. You subtract any increase the installation adds to your home’s value. If the heater cost $3,000 and your home’s value rose by $1,000, only $2,000 is a medical expense. If value didn’t rise at all, the whole cost counts.9Internal Revenue Service. Publication 502 (2025), Medical and Dental Expenses
You claim it on Schedule A, and only the portion of total medical expenses above 7.5 percent of your adjusted gross income is deductible.10Internal Revenue Service. Topic No. 502, Medical and Dental Expenses Between the AGI floor and the home-value offset, few taxpayers end up with much to write off. If you go this route, keep the physician’s written recommendation and an appraisal showing home value before and after.
Records to Keep
Whichever treatment applies, a paper trail protects you:
- The purchase receipt and invoice, showing the unit cost and any separately stated labor.
- Proof of the installation date, such as a contractor’s completion certificate, permit sign-off, or dated invoice. This fixes the depreciation start date and confirms a 2025 install for anyone still claiming the expired credit.
- The manufacturer’s certification statement, if you’re claiming the 2025 credit.
- A physician’s letter, if you’re claiming the medical deduction.
The general IRS rule is three years after filing. For anything tied to your home’s basis or a depreciated business asset, keep the records until at least three years after filing the return for the year you sell or dispose of the property.5Internal Revenue Service. How Long Should I Keep Records For a home you own for two decades, that means holding onto a water heater receipt for the full stretch. Digital storage makes it painless.