Payback
How long a higher upfront heater cost takes to recover
When one heater costs more to install and less to run, the recovery depends on three inputs: the installed-cost difference, the seasonal operating-cost difference, and how long you intend to own the pool. Either difference can change sign with real quotes and energy prices, so the worksheet reports both before it reports a payback.
The operating gap is derived; the install gap is not
The annual operating difference on this page is computed from your pool, your climate and published energy prices — the same chain the main calculator runs. For the default pool in Phoenix, AZ, a heat pump costs $1,662 a season and natural gas $4,291, a difference of $2,629.
The install difference is not derivable. Installed pool-heater prices depend on your gas run, your electrical panel, your equipment pad, your local labour rate and what the contractor's month looks like. This site does not publish an install cost, because any number it published would be invented. The calculator asks you for two quotes instead.
Your two quotes against your operating gap
Get both quotes first. Everything else here is arithmetic.
Installed-cost difference (heat pump minus gas) $2,300positive means the heat pump costs more upfront
Operating-cost difference (gas minus heat pump) $2,629$4,291 gas against $1,662 heat pump; positive favors the heat pump
Payback 0.9 seasonsinside your ownership window
Net position after 10 seasons $23,988savings accumulated minus the install premium
Every pairing, not just the popular one
| Swap | Installed-cost difference | Operating-cost difference | Payback | Net after 10 seasons |
|---|---|---|---|---|
| Heat pump vs natural gas | $2,300 | $2,629 | 0.9 seasons | $23,988 |
| Heat pump vs propane | $2,300 | $5,334 | 0.4 seasons | $51,035 |
| Heat pump vs electric resistance | $4,300 | $7,095 | 0.6 seasons | $66,650 |
| Natural gas vs electric resistance | $2,000 | $4,466 | 0.4 seasons | $42,662 |
In these placeholder rows, the resistance comparisons show a larger operating-cost difference than the gas comparison. Replace every installed price and energy rate before treating that pattern as yours; the first row is especially sensitive to both quotes and the length of your season.
What happens if energy prices move
| Gas price scenario | Gas season cost | Heat-pump saving | Payback |
|---|---|---|---|
| 0.50× today's gas price | $2,145 | $483 | 4.8 seasons |
| 0.75× today's gas price | $3,218 | $1,556 | 1.5 seasons |
| 1.00× today's gas price | $4,291 | $2,629 | 0.9 seasons |
| 1.50× today's gas price | $6,436 | $4,774 | 0.5 seasons |
| 2.00× today's gas price | $8,582 | $6,920 | 0.3 seasons |
A payback figure computed at one moment's prices is a snapshot, not a forecast. This site does not project energy prices, because nobody can, and a page that quietly assumed three percent annual escalation would be manufacturing the answer. The table above is offered instead: decide for yourself which column you believe.
The horizon the federal analysis uses
A payback is only meaningful against a life. The Department of Energy had to settle on one when it set the current pool-heater standards, and it published the figure it landed on and the data behind it:
For the final rule, DOE updated its methodology to include the latest data including RECS 2020, CBECS 2018, and shipment and other data from 2022 PKdata. This resulted in the same average lifetime value of 11 years.
What it settles here Eleven years is the population-average lifetime used in that federal analysis, not a guaranteed service life or a universal cutoff. Compare a calculated recovery period with the warranty, the service conditions and how long you expect to own the pool.
Use the federal lifetime as a reference point, not a promise about either quote. This calculator does not assign either heater an unsourced service life; the horizon that applies to your decision is the shorter of the life you can support from the product and installation evidence and your expected ownership.
The same rulemaking is candid about why pool-heater buyers rarely learn from the decision:
The installation of a new or replacement pool heater is done infrequently, as evidenced by the mean lifetime for pool heaters. Additionally, it would take at least one full pool heating season for any impacts on operating costs to be fully apparent.
What it settles here This is the reason a payback calculation is worth doing before you buy rather than discovering the answer afterwards: the feedback loop on a pool heater is one purchase a decade and one full season before the operating cost is even visible, so nobody accumulates the experience that would let them judge it by instinct.
Four things that break a payback calculation
- Equipment life. A recovery period longer than the equipment's actual service life does not recover the premium. Use the warranty and service conditions from the products in your quotes; this model supplies no lifetime estimate.
- Selling the house. The payback horizon is how long you own it, not how long the equipment lasts.
- Rebates. Utility and state rebates for heat pumps change the install premium directly and can move a marginal payback to an obvious one. They vary by utility and expire; check yours rather than assuming.
- Usage drift. People with cheap-to-run heaters heat more, and people with expensive ones quietly stop. The saving above assumes identical usage on both.