Product Overview

Pentair MasterTemp 300 (460734) – High-Efficiency 300,000 BTU Natural Gas Pool & Spa Heater
Delivering professional-grade heating power in a compact body, the MasterTemp 300 combines reliability, energy efficiency, and smart controls. It’s the go-to solution for larger residential pools or spas that need rapid heat-up and consistent performance without the bulk or noise of older units.

• Heating Capacity: 300,000 BTU Input

• Fuel Type: Natural Gas

• Electrical: 120/240 V Single Phase, 60 Hz

• Weight: ≈136 lbs

• Warranty: 2 Years (when professionally installed)

Call-out Badges: Low NOx Certified • Eco-Select Choice • Compact Design • High-Output Performance

Ideal For

• Larger in-ground pools and spas needing quick, consistent heating

• Homeowners upgrading from legacy 250–300 K BTU gas heaters

• Tight pad installations requiring a small-footprint, lightweight unit

• Users focused on dependable, low-emission, high-efficiency performance

Key Features

300,000 BTU High-Capacity Heating — Delivers robust thermal output to quickly bring large pools and spas to temperature.
Why it matters: Ideal for extended swim seasons or cooler climates.

Compact Composite Cabinet — Corrosion-proof housing withstands outdoor conditions year-round.
Why it matters: Longer lifespan, even in coastal or high-humidity areas.

Rotating Digital Display & Diagnostics — Simplifies setup, monitoring, and maintenance with intuitive readouts.
Why it matters: Makes troubleshooting and control effortless.

Low NOx Burner System — Delivers cleaner combustion that meets or exceeds emission standards.
Why it matters: Environmentally responsible heating without sacrificing performance.

Benefits

• Powerful and Fast: Quickly recovers water temperature after use for uninterrupted comfort

• Energy-Efficient: High thermal efficiency saves on fuel costs over the season

• Quiet Operation: Engineered combustion system keeps noise to a minimum

• Durable Design: Composite shell resists rust, UV, and weather exposure

• Compact Footprint: Fits standard equipment pads and retrofit installations

Specs & What’s in the Box

Specifications

• Dimensions: 23″ W × 32.6″ D × 28″ H

• Weight: ≈136 lbs

• Materials: Rugged composite cabinet with copper or cupro-nickel heat exchanger

• Gas Connection: ¾″ NPT

• Electrical: 120/240 V single-phase connection

• Fuel Type: Natural Gas

In the Box

• Pentair MasterTemp 300 Natural Gas Heater (460734)

• User manual and installation guide

• Mounting hardware and fittings

Compatibility & Replacements

Works with: Standard residential in-ground pool and spa systems using natural-gas supply
Replaces: Older Pentair MiniMax and similar 250–300 K BTU heaters
Not compatible with: Propane models (use 460735) or ASME-certified installations (model 461040)

Trust Builders

• ⭐⭐⭐⭐⭐ Pentair’s most popular high-capacity residential pool heater

• Backed by a two-year limited warranty

• Supported through Pentair’s authorized service network

• Designed and assembled in the USA

Install Steps (Compact)

1. Turn off power and gas supply

2. Remove existing heater and prepare plumbing connections

3. Mount MasterTemp 300 level on pad and connect water and gas lines

4. Connect 120/240 V power and configure digital controls

5. Test operation and check for leaks and proper heating performance