Every September we have the same conversation. The weather is still pleasant, the pool has dropped to about 70 degrees, and nobody wants to get in. A heater is the difference between a pool you use four months a year and one you use six or seven.
Here is what the three options actually do, what they cost to run in this climate, and how to tell which one fits your setup.
How many weeks does a heater really buy you?
In the Tri-Cities, an unheated pool is comfortable roughly from late May through early September. A properly sized heater reliably extends that into late October on the back end and pulls the start forward into April.
That is not a small change. It is close to doubling your season, and it is the difference between the pool being a July thing and being a genuine part of the house.
Heat pumps
A heat pump moves heat out of the surrounding air into your water rather than generating heat directly. That makes it by far the most efficient option to run, often several times more efficient than gas per unit of heat delivered.
The tradeoff is speed and temperature range. A heat pump warms water gradually over a day or two rather than in a few hours, and its efficiency drops as the air gets colder. Once outside temperatures fall below the low fifties, it works much harder for much less. For extending a season into October, that is fine. For heating a pool in December, it is the wrong tool.
This is the option we recommend most often, because most people want a warm pool for more of the season rather than instant heat on demand.
Gas heaters
A gas heater burns propane or natural gas and heats fast. You can raise a pool several degrees in a matter of hours regardless of what the air is doing.
That makes it the right pick if you use the pool occasionally and want it hot for a specific weekend, or if you want to push the season well past when a heat pump gives up. The catch is running cost. Gas is considerably more expensive per hour of operation, so heating a large pool continuously adds up quickly.
Solar
Solar heating circulates pool water through panels, usually roof mounted. Once installed, it costs essentially nothing to run.
It is also the least controllable. Output depends entirely on sun, so a cloudy stretch in October gives you very little, and it adds a handful of degrees rather than a dramatic change. It works best as a supplement in a sunny yard, not as your only source of heat.
Sizing matters more than brand
An undersized heater is the most common mistake we see, and it is an expensive one because it never quite gets there while still running constantly. Sizing depends on your pool volume, surface area, how exposed the yard is to wind, and what temperature you actually want to hold.
A pool cover changes this calculation more than people expect. Most heat loss happens at the surface through evaporation, so a solar or thermal cover can cut your heating cost substantially. If you are buying a heater, buy a cover in the same conversation.
Get sized before you buy
Bring us your pool dimensions and a rough idea of how long you want the season to run, and get a heater quote. If a heater does not make sense for your setup, we will say so.
Our pool service team installs and services heaters across Johnson City, Kingsport, and the surrounding area, and covers areas we serve throughout the region. Fall is a good time to schedule, before heater work stacks up in spring.
Not sure whether to heat or close up instead? See our guide on when to close your pool.
