Quick answer: The EcoSmart Smart Pool 27 (27kW, ~$949) is the best all-around electric pool heater — it puts out roughly 92,000 BTU/hour with self-modulating technology that ramps power up or down instead of tripping a breaker, and it’s rated to raise temperature 1–1.5°F per hour per EcoSmart’s spec sheet. For a spa or pool under 800 gallons, the smaller Raypak E3T (11kW, ~$1,000–$1,100) or the budget EcoSmart Smart Spa 11 (11.8kW, ~$499) is a better fit. Electric resistance heaters skip the gas line and the compressor entirely — you just need a dedicated high-amp circuit and a spot inline with your pump.
Electric resistance heaters work differently than gas heaters or heat pumps: a heating element sits directly in the water line and converts electricity to heat with no combustion and no refrigerant cycle. That makes them simple, weatherproof, and cheap to buy — but because they don’t multiply energy the way a heat pump’s compressor does, they cost more per BTU to run. They make the most sense for spas, small above-ground pools, or as a fast-heat backup to a slower heat pump.
Best electric pool heaters at a glance
| Heater | Output | Best for | Price | Rating |
|---|---|---|---|---|
| EcoSmart Smart Pool 27 | 27kW / ~92,000 BTU | Best overall | ~$949 | ★★★★★ |
| Raypak E3T | 11kW / 37,534 BTU | Trusted brand, spas | ~$1,000–$1,100 | ★★★★☆ |
| EcoSmart Smart Spa 11 | 11.8kW / ~40,000 BTU | Best budget | ~$499 | ★★★★☆ |
| EWANYO 15kW | 15kW / ~51,000 BTU | Small above-ground pools | ~$700 | ★★★☆☆ |
1. EcoSmart Smart Pool 27 — Best Overall
EcoSmart Smart Pool 27 (27kW Electric Tankless Pool Heater)
- 27kW output (~92,000 BTU/hour equivalent) — enough for a larger above-ground pool or a small in-ground pool, not just a spa.
- Self-modulating technology adjusts power draw to demand instead of running flat-out, per EcoSmart's spec sheet.
- Rated for a 1–1.5°F/hour temperature rise at full output.
- Needs a 240V circuit and three 40A double-pole breakers — this is not a plug-and-play install.
The Smart Pool 27 is the rare electric resistance heater with enough output to matter for more than a spa. It won’t out-cost a heat pump on a full season of daily heating, but if you need to bring a pool up to temperature fast — a weekend guest list, a cool snap, or a pool too small to justify a full heat-pump install — it’s the most capable electric option we found. Want it before the weekend arrives? Try Amazon Prime free for 30 days and get two-day delivery so a shipping delay doesn’t cost you the warm weekend.
2. Raypak E3T — Best Trusted Brand
Raypak E3T Digital Electric Heater (11kW)
- From Raypak, one of the three major brands (with Hayward and Pentair) most pool professionals install.
- 11kW model delivers 37,534 BTU — sized for spas and small above-ground pools.
- Also sold in 5.5, 18, and 27kW sizes if 11kW doesn't match your volume.
- Costs more than generic-brand electric heaters at the same kW, but backs it with wider parts and service availability.
If you’d rather buy from a brand with a service network behind it, the E3T is the safer pick — we cover the full Raypak lineup, including the AVIA gas heaters and R8450ti heat pump, in our best Raypak pool heater guide.
3. EcoSmart Smart Spa 11 — Best Budget
EcoSmart Smart Spa 11 (11.8kW Tankless Electric Spa Heater)
- 11.8kW output (~40,000 BTU/hour equivalent) — sized for spas up to roughly 800 gallons.
- Activates at a 10.0 GPM flow rate with digital thermostat control, per EcoSmart's published spec sheet.
- Compact, wall-mountable cabinet built for inline plumbing rather than a standalone pad.
- Needs a dedicated 60A breaker and 6 AWG wiring — budget for an electrician if you don't already have the circuit.
At roughly half the price of the Raypak E3T for a similar kW rating, the Smart Spa 11 is the heater to buy if you just need a hot tub or small spa warm and don’t need a recognized brand name behind it.
4. EWANYO 15kW — Best for Small Above-Ground Pools
EWANYO Electric Pool Heater (15kW)
- Manufacturer-rated for pools up to about 1,981 gallons — a step up in volume from the spa-sized units above.
- Digital touch-screen display with over-current, over-temperature, and low-flow protection built in.
- Generic import brand — expect a shorter warranty and thinner support than EcoSmart or Raypak.
- Also sold in 11kW and 18kW sizes depending on your pool's gallon count.
This is the option for a small soft-side or above-ground pool that’s bigger than a spa but still too small to justify a heat pump install — see our dedicated best above-ground pool heater guide if your pool runs larger than about 2,000 gallons.
Electric heater vs. heat pump vs. gas: which should you buy?
Electric resistance is the simplest technology of the three — no combustion, no refrigerant, just a heating element in the water path — but it’s also the most expensive to run per BTU delivered. According to the U.S. Energy Information Administration, the average U.S. residential electricity rate in 2026 is about 18.83¢/kWh; running an 11kW resistance heater for an hour costs roughly $2.07 in electricity alone, while a heat pump with a COP of 5–6 delivers the same heat for a fraction of that because it moves heat rather than generating it directly. For the full monthly-cost math across all three heater types, see our pool heating cost breakdown. Electric heaters earn their keep on spas, small pools, and as a fast-heat backup — not as the primary heater for a full-size in-ground pool run daily all season.
The bottom line
For most buyers who’ve decided electric resistance is the right fit, the EcoSmart Smart Pool 27 is the best overall pick — it’s the only unit here with enough output for more than a spa. Choose the Raypak E3T if you want a recognized pool-equipment brand, the EcoSmart Smart Spa 11 to save money on a spa-only install, and the EWANYO 15kW for a small above-ground pool on a tight budget.