How long does a pool heater last?
Updated August 2026
A pool heater's lifespan splits sharply by type: a gas heater lasts 5–10 years while an electric heat-pump heater runs 10–20 years. The gap comes from how they make heat. A gas heater burns fuel and pushes hot combustion gases across a copper or cupronickel heat exchanger, which corrodes and scales over time, whereas a heat pump moves ambient heat with a refrigerant loop and never subjects its exchanger to a flame. In both, water chemistry is the deciding factor, because low pH and high calcium scale or eat the heat exchanger faster than anything else. Keeping the water balanced is what carries either type to the top of its range.
Lifespan by type and situation
| Type or situation | Typical lifespan | Why |
|---|---|---|
| Gas heater (natural gas / propane) | 5–10 years | Combustion and scale corrode the heat exchanger |
| Electric heat-pump heater | 10–20 years | No flame; the refrigerant loop is gentle on parts |
| Heat exchanger | 5–12 years | The core wear part; chemistry decides how fast it goes |
| Salt-pool gas heater | Low end of range | Salt speeds corrosion without a proper cupronickel exchanger |
| Left wet over a freeze | Cracked exchanger | Water frozen inside splits the tubing |
| Chronically low pH | Cut in half | Acidic water eats copper from the inside out |
Signs yours is near the end
- Water that heats slowly, or a heater that fires briefly then shuts off on a fault
- Rust flakes, soot, or green corrosion visible around the burner tray or exchanger
- Error codes for low flow, high limit, or ignition failure that keep returning
- A puddle under the heater from a leaking, corroded heat exchanger
- Rising gas or electric bills as scale insulates the exchanger and steals efficiency
- A rotten-egg or gas smell at a gas unit, meaning combustion problems to service now
How to add years
Balanced water is what a pool heater lives or dies on. Keep pH in the 7.4 to 7.6 band and calcium hardness in range, because acidic water dissolves the copper heat exchanger and scale-forming water insulates and clogs it, and the exchanger is the most expensive part in the box. Run the pump long enough for good flow, since a heater starved of water trips out and stresses its controls. Winterize a gas heater in cold climates so trapped water cannot freeze and crack the exchanger. The heater maintenance checklist keeps the routine straight, a healthy pool pump supplies the flow it needs, and when the exchanger finally corrodes through, the repair-or-replace guide and a primer on how a pool heater works help you choose the next step.
What it costs to replace: plan on $2,500–6,000 installed. Replacing on your own schedule, before it fails, is almost always cheaper than the emergency version. The home maintenance cost calculator helps you set the money aside before it comes due.
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Track your home's systems, free for 30 daysFrequently asked questions
Is a pool heat pump better than a gas heater?
For lifespan and running cost, usually yes. A heat pump lasts 10–20 years against a gas heater's 5–10, and it is far cheaper to run because it moves heat rather than burning fuel to make it. The trade-off is speed and climate: gas heats a pool fast and works in any temperature, while a heat pump warms slowly and loses output once the air drops below the mid-50s Fahrenheit. Gas makes sense for occasional quick heating; a heat pump wins for a pool you keep warm all season.
Why did my pool heater stop working?
Most no-heat calls trace to flow or chemistry, not a dead heater. Low water flow from a dirty filter, a clogged pump basket, or a closed valve trips the heater's safety switch and it refuses to fire. A scaled or corroded heat exchanger from unbalanced water is the next suspect, followed by a failed igniter or pressure switch on gas models. Check the filter and flow first, confirm the water is balanced, and clear any error code before calling a tech; many shutdowns are the heater protecting itself.
How much does it cost to replace a pool heater?
Plan on $2,500–6,000 installed, with the type driving most of the spread. A gas heater sits toward the lower and middle of that range, while an electric heat pump usually runs higher up front but costs far less to operate over its longer life. The exchanger, gas valve, and control board on an existing unit can sometimes be repaired for $300–1,000, which is worth pricing on a heater under 7 years old. Past that age, especially with a corroded exchanger, a full replacement is usually the smarter spend.