How much does a propane water heater cost?

Q: How much does a propane water heater cost?

A propane tank water heater costs $700 to $2,500 installed according to Fixr (January 2026), and a propane tankless unit $1,400 to $3,500 per This Old House (June 2026). The appliance is essentially a natural gas unit, so the purchase price is similar. What differs is the running cost, about $350 a year for tankless against about $250 for natural gas, and the fuel tank itself, which neither source includes.

What it costs

Type	Installed cost	Source
Propane tank water heater	$700 to $2,500	Fixr
Natural gas tank, for comparison	$700 to $2,700	Fixr
Propane tankless, unit only	$500 to $2,000	This Old House
Propane tankless, labor	$900 to $1,500	This Old House
Propane tankless, total	$1,400 to $3,500	This Old House
Natural gas tankless, total	$1,650 to $3,500	This Old House

The appliance prices sit right on top of natural gas at both ends. This Old House notes propane systems begin at about $700 before tank installation, and Fixr explains why the hardware is so similar: most units that run on natural gas can also use liquid propane, and a few need only a converter if they are currently set up for natural gas. There are also units built for propane from the start.

The cost neither source includes

The propane tank. Both sources price the water heater. Neither prices the tank in the yard, the regulator, the line to the house or the delivery contract. This Old House says explicitly that propane systems begin at $700 "before tank installation".

If you already run propane for a furnace, a range or a dryer, that infrastructure exists and this page's figures are complete. If you do not, a propane water heater is not a $700 appliance decision, it is the start of a fuel supply, and we are not going to invent a number for something neither source publishes.

That is the single most useful thing to know before comparing a propane quote with an electric one.

Running cost

Fuel, tankless	Per year	Source
Natural gas	about $250	Fixr
Propane	about $350	Fixr
Electric	about $600	Fixr

Fixr's framing: propane is more costly than natural gas, but usually cheaper than oil. It also describes propane as a cleaner and more efficient fuel than the alternatives it sits between.

For tank units, neither source publishes a propane-specific annual figure. Fixr's gas tank operating costs are $300 to $450 a year for a 40-gallon unit and $325 to $475 for a 50-gallon one. Our reading, stated as such: propane will run somewhat above those, in the same proportion as the tankless figures, roughly 40% higher. We are flagging that as an inference, not a published number.

Where propane makes sense

No natural gas line. This is the case it exists for. This Old House: propane tankless heaters work best in homes without natural gas access. Running a new natural gas line is priced at $1,500 to $2,300 by This Old House, and that assumes a main to connect to.

You want gas performance without the main. A propane tankless unit delivers 8 to 10 gallons per minute (This Old House), enough for multiple fixtures at once. An electric tankless unit delivers 3 to 8 GPM and needs 120 to 160 amps of dedicated service most houses do not have. See electric or gas tankless.

Cold incoming water. The same flow-rate advantage matters more in cold climates, where the unit has to raise incoming water further.

Where it does not

Against a heat pump, on running cost. Fixr's hybrid figures are $200 to $350 a year for a tank unit, which is at or below propane tankless, with no fuel tank, no delivery contract and a 30% federal tax credit up to $2,000. In an area with no gas main, that is the comparison worth running before committing to propane.

On fuel price volatility. Neither source discusses it and we will not pretend to numbers, but a delivered fuel and a metered utility are different kinds of exposure. That is a judgement, not a published finding.

Repairs and maintenance

Fixr prices propane water heater repairs at $150 to $750, identical to natural gas, and states the reason directly: propane water heaters are simply a type of gas water heater, so the repair costs are the same and the possible faults are identical. Valve problems and tank issues head the list.

That also means everything on our gas-unit pages applies: the venting requirement, the pilot light and thermocouple faults, and the 8-to-12-year tank life.

What to ask for in a quote

Whether the unit is built for propane or is a natural gas unit with a conversion kit, and whether that kit is included.
Whether the quote covers anything to do with the propane tank, the regulator or the line, or only the water heater.
The venting arrangement, which propane needs exactly as natural gas does.
A comparison quote for a heat pump unit, if you have no gas main. On published running costs it is the closest competitor.

Sources

Price figures are national US ranges from the sources above as of the date shown. Your local price depends on labor rates, permits and site conditions. Read how we get our numbers.