Product Overview

The Sta-Rite Max-E-Therm 400 HD (Model SR400HD) is a premium, high-efficiency natural gas pool heater engineered for fast heat-up times, exceptional durability, and long-lasting performance. Delivering 400,000 BTUs, this heater is ideal for residential and commercial pools that demand powerful, reliable temperature control.

The HD (Heavy-Duty) version includes a Cupro-Nickel heat exchanger, providing enhanced resistance to corrosion, saltwater exposure, and aggressive water conditions. Its lightweight composite exterior withstands harsh weather while maintaining a quiet, energy-efficient operation.

Built for serious performance in demanding environments, the Max-E-Therm 400 HD ensures warm, comfortable water whenever you need it.

Ideal For

• In-ground pools and spas requiring high-capacity heating

• Saltwater or high-use pools needing a corrosion-resistant heat exchanger

• Commercial or large residential pools

• Pool owners seeking fast heat-up times and reliable temperature performance

• Replacement for older Max-E-Therm or MasterTemp heaters

Key Features

• 400,000 BTU Output: Rapidly heats large pools and spas with consistent, powerful performance.

• HD Cupro-Nickel Heat Exchanger: Superior durability and corrosion resistance for saltwater and chemical-rich environments.

• Energy-Efficient Operation: Meets industry efficiency standards while reducing operating costs.

• Lightweight Composite Housing: Rugged, rustproof exterior that resists heat, corrosion, and UV exposure.

• Compact Design: Space-saving footprint ideal for tight equipment pads.

• Quiet Operation: Advanced combustion system minimizes noise.

• Digital Controls: Easy-to-use LED display with temperature settings, diagnostics, and service alerts.

• Versatile Voltage: Compatible with 120V or 240V electrical setups.

• Reliable Sta-Rite Engineering: Trusted construction backed by decades of heater innovation.

Benefits

• Heats Quickly: High BTU rating ensures rapid warm-up for extended swim seasons or year-round spa use.

• Built for Harsh Conditions: HD model is ideal for pools with fluctuating water chemistry.

• Lower Ownership Costs: High efficiency helps reduce gas consumption and long-term energy expenses.

• Quiet Backyard Experience: Runs quietly, maintaining a peaceful pool environment.

• Long Service Life: Composite materials and Cupro-Nickel exchanger extend durability and reliability.

Customer Q&A

Q: What makes the HD version different?
A: The HD model includes a Cupro-Nickel heat exchanger, offering superior corrosion resistance—ideal for saltwater or heavily used pools.

Q: What size pool is this heater suitable for?
A: The SR400HD is powerful enough for large in-ground pools, spas, and commercial installations.

Q: Can it run on either 120V or 240V?
A: Yes. The unit supports 120/240 VAC, simplifying installation.

Q: How heavy is the heater?
A: The unit weighs 127 lbs, making it lighter than many comparable heaters.

Q: Is this heater suitable for outdoor installation?
A: Absolutely—the composite housing is weather-resistant and built for outdoor equipment pads.

Specifications

• Model: SR400HD

• BTU Output: 400,000 BTU

• Fuel Type: Natural Gas

• Voltage: 120/240 VAC

• Frequency: 60 Hz

• Heat Exchanger: Cupro-Nickel (Heavy Duty)

• Weight: 127 lbs

• Housing: Corrosion-resistant composite

• Ignition: Electronic

• Application: Large in-ground pools & spas

• Manufacturer: Sta-Rite / Pentair