5 Things to Know About Pool Heater Size

Bigger isn’t always better for pool heaters. A 100,000 BTU unit on a small above-ground pool will short-cycle, wasting gas and wearing out faster.

Most above-ground pools need 50,000 to 75,000 BTUs. These pools typically hold 5,000 to 15,000 gallons, so a monster heater is unnecessary.

Use the 50,000 BTU per 10,000 gallons rule. This raises the water temperature by 10°F in a couple hours on an average day.

For a common 12,000 to 15,000 gallon pool, 75,000 BTUs is the sweet spot. It balances heating speed and efficiency without overkill.

Only push toward 100,000 BTUs in colder climates or for faster heating. But never go higher than that for an above-ground pool.