Pool Heater Cost: Average Prices & Cost Factors

A pool heater lets you swim earlier in spring and later in fall, and it keeps the water comfortable on cool nights. Heaters differ a lot in what they cost to run each month, so the cheapest unit can cost the most to own.

Three questions shape the budget: what type of heater fits your climate and fuel supply, how big it needs to be for your pool, and what hookups the installer has to add or change.

Heaters are sized by output, measured in BTUs, and by the volume of water they need to warm. A larger pool needs more output. The table below shows the cost of the heater unit alone, before labor and hookups.

An undersized heater runs for a long time and may never reach the temperature you want. An oversized unit costs more up front. Ask the installer to size the heater for your pool volume, your climate, and how warm you want the water.

Running costs often matter more than the purchase price over the years. Monthly bills depend on the fuel, local utility rates, pool size, how warm you keep the water, and whether the pool has a cover.

Solar is the cheapest to run, since sunlight is free, but it relies on sun and roof or ground space. Heat pumps use electricity efficiently and are common for pools used across a long season. Gas heaters warm a pool fast, which suits occasional use. Electric resistance heaters can be the costliest to run.

• Gas or propane. Heats quickly and works in any weather, which suits spas and weekend use. Fuel is a recurring cost, and it needs a gas line or tank.
• Heat pump. Efficient and good for steady, season-long heating. It works best in mild weather, and the unit costs more.
• Solar. Very low running cost. It needs panels with enough sun exposure, and it heats more slowly.
• Electric resistance. Simple and compact, but it can be expensive to run for large pools.

Match the type to how you use the pool. Occasional use suggests gas, and daily use through a long season points to a heat pump or solar.

• Heater type and size. Bigger and more efficient units cost more.
• Fuel connection. New gas lines or electrical circuits add to the bill.
• Distance. A heater far from the pool equipment pad needs longer plumbing.
• Venting and clearances. Gas units need proper venting and space.
• Permits. Gas and electrical work usually require permits.
• Replacement versus new install. Swapping like-for-like is typically simpler.
• Local labor rates. Pool service pricing varies by region.

Replacing an old heater often costs less than a first-time install, because the plumbing, gas line, or circuit may already be in place. A new model may still need updates to meet current code, and a different fuel type means new hookups.

If your existing heater has failed, ask whether a repair makes sense or whether the age and condition point toward replacement. A technician can diagnose the problem, and the answer often depends on the heater's age and the part that failed.

Heater work involves gas, electricity, or both, and it sits near water. Leave it to a licensed pool contractor, plumber, or electrician. Gas units need correct venting to avoid carbon monoxide risk, and electrical heaters need proper bonding and grounding. Most areas require permits for this kind of work, and the contractor should handle them.

Keep the installation paperwork and the warranty terms. Some manufacturers require professional installation for the warranty to be valid.

• Use a pool cover. It reduces heat loss and evaporation.
• Set a reasonable temperature rather than the maximum.
• Heat only when you plan to swim.
• Add a windbreak if the pool sits in an exposed spot.
• Consider a heat pump or solar if you swim through a long season.

• What size heater do you recommend for my pool, and why?
• Does the price include gas line, wiring, venting, and permits?
• What will it cost per month to run at the temperature I want?
• What warranty covers the heater, the heat exchanger, and labor?
• Who handles service if it fails?