Pool Heating near you

Pool heaters are covered products under federal appliance efficiency law, and the standard is written into 10 CFR 430.32. Gas-fired pool heaters manufactured on and after April 16, 2013 and before May 30, 2028 must have a thermal efficiency of not less than 82 percent. For units manufactured on and after May 30, 2028, the rule changes shape: gas-fired pool heaters and electric pool heaters must meet an integrated thermal efficiency standard, which measures the appliance more completely than a single burner efficiency figure does.

What this means for a homeowner is modest but useful. Any new gas heater sold to you today already meets the 82 percent floor, so a quote that presents that as a premium feature is selling you the law. Comparisons between two current gas heaters therefore come down to sizing, controls, venting, materials and warranty rather than to a headline efficiency number, and comparisons between fuel types come down to what you pay for the fuel where you live.

It also means the second half of this decade is a transition. If you are installing a heater that you expect to run for many years, ask the installer how the unit is rated, whether a successor model is expected, and what parts availability looks like, because a rule change is usually followed by a product change.

The right heater depends less on the pool than on the pattern of use. If you want the water hot on demand, in the shoulder season, on a cold evening, with little notice, a gas heater is the only one of these that behaves that way, and its running cost is the price of that responsiveness. If you want a longer season at a steadier temperature and are willing to plan a day ahead, a heat pump is the more economical way to hold a pool at temperature, with the caveat that its output falls as the air cools, which makes it a better fit in warm and humid regions than in a cold, dry shoulder season.

Efficiency for a heat pump is described by its coefficient of performance. EPA's pool guidance says coefficients of performance typically range from 3 to 7, and that the higher the number, the more efficient the heater, which is the single most useful specification to compare between two units. A heat pump with a high coefficient delivers several units of heat for each unit of electricity, which is why it can undercut resistance heating so dramatically.

Solar sits outside the comparison because its running cost is the pump time and nothing else. Its limitation is that you take what the day gives you, so it lengthens a season rather than guaranteeing a temperature, and it needs roof or ground area and a route for the plumbing. In much of the Sun Belt, solar plus a good cover is enough on its own; in the north it is a shoulder-season extender rather than a primary heater.

Nearly every heater fault a homeowner meets is really a flow fault. Heaters have pressure and flow switches that prevent them firing into a restricted circuit, so a loaded filter, a blocked basket, a closed valve, a low water level or a failing pump will all present as a heater that lights and cuts out or never lights at all. Check the filter pressure and the baskets before anyone is called to look at the heater itself.

Water balance is the second killer, and it works slowly enough to be invisible. Scaling water coats the heat exchanger and steals the heat transfer the whole appliance depends on, while aggressive water attacks the metal inside it. A heater that has become noisy, slow to reach temperature or prone to short cycling after a season of neglected chemistry is usually telling you what the water has been doing.

Gas heaters add a third category that is not a homeowner diagnostic. Venting, gas supply, combustion and ignition are licensed trade territory, and a heater that smells of gas, sounds wrong on ignition, has sooting around the vent or has been flooded should be shut off and handed to a qualified professional rather than investigated. The same applies to the electrical side: CPSC recommends ground-fault circuit-interrupter protection on pumps and electrical equipment around pools and monthly testing of GFCIs, and treats any tingle in the water as a reason to get out and get the system inspected.

A heater bought to add weeks at either end of the season is used differently from one bought to hold a temperature all summer, and the cheapest strategy usually combines a modest set temperature with disciplined cover use. Covering overnight is when the difference shows, because the temperature gap between water and air is largest and the wind is often up.

In cold-winter states the heater is also part of the closing procedure rather than something to forget. It has to be drained as part of winterization, since water left in a heat exchanger over a hard freeze is the most expensive freeze damage a pool can suffer. In mild-winter states, where pools run year-round, the heater's freeze protection setting is worth configuring before the first cold night rather than during it.

Solar has its own seasonality: collectors deliver most in the months you least need them, and the shoulder-season benefit depends heavily on orientation and shading. That is a design question at installation, not something to be tuned later, so ask for the expected contribution in your months rather than an annual figure.