A high-use pool or pool-and-spa where fuel cost decides it, and a pad that can handle a condensing heater's condensate drain.
★★★★★ 230+ Google Reviews · CPO C-105377 · 40+ years of combined founder experience
Sizing comes first.The right heater is set by your pool's surface area and the temperature rise you want, and by the flow your pump and plumbing deliver. Start with the heater size calculator; we confirm it on site before quoting.
Our own score for what saves you money and headaches in South Florida.
ETi 400
4.4
out of 5
From the manufacturer's documents listed under Sources. Where the documents disagree, the table says so.
| Manufacturer model | ETi 400 High Efficiency Heater, natural gas, ASME listed, P/N 461113 |
|---|---|
| BTU input | 400,000 BTU/hr |
| Thermal efficiency | 96% (tested per ANSI Z21.56:19/CSA 4.7:19 2019, section 5.10) |
| Heat exchanger | Titan-Tough direct-fire titanium, ASME certified construction; design temperature rise 30°F ±5°F |
| Fuel | Factory configured for natural gas; propane conversion kit P/N 476072 available |
| Emissions and certification | Certified for low NOx emissions by a third-party test lab and communicated to SCAQMD for Rule 1146.2; ASME certified, CSD-1 compliant, CSA certified to ANSI Z21.56/CSA 4.7 |
| Water flow | 40 GPM minimum, 120 GPM maximum (external bypass required above 120 GPM); maximum ΔT 35°F, minimum ΔT 25°F |
| Gas supply pressure | Natural gas 4" w.c. minimum to 10.5" w.c. maximum; propane 4" to 12" w.c.; maximum pressure change 2" w.c. |
| Gas pipe sizing (natural gas) | 3/4" not permitted; 1" to 20 ft, 1-1/4" to 90 ft, 1-1/2" to 200 ft |
| Venting | Category IV; Schedule 40 PVC, Schedule 80 CPVC or stainless steel. 4" pipe to 120 ft or 6" pipe to 300 ft, less 12 ft per 90° elbow and 6 ft per 45°. Vent gas under 170°F. With 4" pipe the Combustion Air Intake Kit (P/N 475971) must be installed; intake and exhaust at least 36" apart. |
| Condensate | 2 to 4 gallons per hour. Condensate Neutralizer Kit (P/N 475612) strongly recommended; horizontal vent runs slope back toward the heater at 1/4 inch per foot so condensate drains through the neutralizer. |
| Electrical | 120 or 240 VAC, 60 Hz, single phase; 15 A circuit; about 5 A at 120 VAC or 2.5 A at 240 VAC |
| Clearances | 6" from combustible surfaces on the top, exhaust side, header side and door panels; 3 ft between a roof or deck overhang and the top of the exhaust vent; 36" from an air conditioner, heat pump or another gas heater |
| Dimensions and weight | 40" L x 30" W x 46" H; 365 lb crate weight |
| Safety and diagnostics | Two stack flue sensors (SFS activates at 170°F, thermal fuses at 187°F), two automatic gas shut-off switches (150°F), high limit (135°F), air flow switches, water pressure switch and condensate float switch; last five error codes readable from the control pad |
| Controls and automation | 2-wire dry contact through the fireman's switch terminals for IntelliCenter, IntelliTouch or EasyTouch Control Systems, or a time clock. Pentair's ETi 400 manual documents no RS-485 connection. 180° rotating control panel for left or right plumbing orientation. |
Parts
3 years
Labor
3 years
Heat exchanger
Under the parts term
| Parts | 3 years |
|---|---|
| Labor | 3 years |
These are the manufacturer's published terms. Terms can depend on the installer, the dealer program and where the heater was bought, and they change without notice, so we confirm the exact term for your install on the written quote.
Titanium doesn't corrode in pool water, so it's the standard on quality heat pumps and the reason a heat pump can sit on a salt pool for years without exchanger trouble. It costs more, which is why it's rare on gas heaters, and the ETi 400 is the exception here.
See every material side by side on the comparison page.
Most to least forgiving of salt and unbalanced water.
Hayward · Universal H-Series
A larger pool or a pool-and-spa combination that needs fast heat-up in any weather.
App control through automation
Jandy · JXiQ
A larger pool or a pool-and-spa combination that needs fast heat-up in any weather.
App control through automation
Raypak · AVIA HD with NiTek
A larger pool or a pool-and-spa combination that needs fast heat-up in any weather.
Built-in Wi-Fi
Every figure on this page comes from these manufacturer documents. We re-open each one and match the model number, capacity and efficiency before the date moves. How we verify.
| Document | Type | Last checked |
|---|---|---|
| Pentair — ETi 400 Installation and User's Guide (flow, gas pressure, clearances, electrical, error codes)pentair.com | Manual or guide | October 14, 2026 |
| Pentair — ETi 400 Quick Reference Guide (venting, gas line sizing, condensate, certifications)pentair.com | Manual or guide | October 14, 2026 |
| Pentair — 2025-2026 Pool Product Catalog, Heaters & Heat Pumps section (June 2025)pentair.com | Spec sheet or brochure | October 14, 2026 |
| Pentair — High-Performance Pool & Spa Gas Heaters brochure (efficiency, exchanger, dimensions, heat-up times)pentair.com | Spec sheet or brochure | October 14, 2026 |
| Pentair — Pool product warranty information (parts, labor, compressor, exchanger terms and channel conditions)pentair.com | Warranty terms | October 14, 2026 |
Manufacturers revise terms without notice. Treat this page as a starting point and confirm the current terms before you buy. If something here is out of date, tell us and we'll fix it.
Parts: 3 years. Labor: 3 years. These are the manufacturer's terms as published; warranty terms change and can depend on the installer and the channel, so we confirm the exact term for your install on the written quote.
The ETi 400 is rated at 400,000 BTU/hr input. Heater size comes from your pool's surface area and the temperature rise you want, not from gallons, and the pump and plumbing have to deliver the flow the heater needs. Use our heater size calculator for a starting number, and we confirm it on site before quoting.
Not directly. The ETi 400 connects to pool automation through a relay, and the heater has no app of its own.
Titanium doesn't corrode in pool water, so it's the standard on quality heat pumps and the reason a heat pump can sit on a salt pool for years without exchanger trouble. It costs more, which is why it's rare on gas heaters, and the ETi 400 is the exception here.
Every figure on this page comes from the manufacturer's own documents, listed under Sources with the date we last checked them. Manufacturers revise terms without notice, so treat the page as a starting point and confirm the current terms on your quote.
We quote, install and service Pentair heaters across Palm Beach and Broward, managed by us under our Florida Certified Pool/Spa Contractor license (CPC1461731). You get a free on-site sizing visit and one written price. Gas lines, new circuits and refrigerant work are done by licensed contractors we manage.
We call back within 30 minutes during business hours.
