Product Overview

The Sta-Rite Max-E-Therm 400 HD Natural Gas Heater SR400HD is a heavy-duty, high-performance pool and spa heater designed for fast heat-up, reliable operation, and long-lasting durability. With 400,000 BTUs of heating power, natural gas operation, and a cupro-nickel heat exchanger, this HD model is built for demanding residential pool and spa systems.

The Max-E-Therm series is known for its compact footprint, lightweight design, digital controls, and rustproof exterior housing. The SR400HD is a strong option for larger pools, attached spas, and customers who want quick temperature recovery with added heat exchanger protection.

Ideal For

Large residential swimming pools

Pool and spa combination systems

Natural gas pool heating applications

Customers wanting fast pool heat-up

Attached spas needing quick temperature recovery

Heavy-use pool and spa systems

Equipment pads with limited space

Customers wanting cupro-nickel heat exchanger durability

Key Features

400,000 BTU natural gas heating performance

Heavy-duty HD model

Cupro-nickel heat exchanger for added durability

120/240 VAC electrical capability

60 Hz operation

Digital temperature controls

Electronic ignition with no standing pilot

Low NOx heater design

Compact, lightweight Max-E-Therm cabinet

Rustproof Dura-Glas® exterior housing

Designed for fast pool and spa warm-up

Compatible with many pool and spa automation systems

Benefits

The Sta-Rite Max-E-Therm SR400HD delivers powerful 400K BTU heating while offering added durability through its cupro-nickel heat exchanger. This makes it a strong choice for heavier-use systems, tougher water conditions, and pool owners who want a more durable heater option than a standard copper exchanger model.

Its compact, lightweight design helps simplify installation and replacement on many existing equipment pads. Digital controls make temperature adjustment easy, while the natural gas platform provides fast and dependable heating for pools and spas.

Specifications

Compatibility & Ordering Notes

Confirm this is the correct natural gas HD model before ordering.

Verify that 400,000 BTUs is properly sized for the pool or spa application.

Confirm gas line sizing, gas supply, electrical requirements, plumbing layout, venting requirements, equipment pad clearances, and local code requirements before installation.

This model is not for propane systems. For propane applications, use the correct propane Max-E-Therm model.

Professional installation is strongly recommended.

Installed or used heaters may not be eligible for return.

Customer-Facing Q&A

Q: Is SR400HD natural gas or propane?
A: SR400HD is the natural gas version of the Sta-Rite Max-E-Therm 400 HD heater.

Q: How many BTUs is this heater?
A: This heater is rated at 400,000 BTUs.

Q: What makes the HD model different?
A: The HD model includes a cupro-nickel heat exchanger, which is designed for added durability in more demanding pool and spa applications.

Q: Can this heater run on 120V or 240V?
A: Yes. This model is designed for 120/240 VAC operation.

Q: What is the barcode for SR400HD?
A: The barcode is 788379804084.

Q: Does this heater use a standing pilot?
A: No. The Max-E-Therm uses electronic ignition and does not require a standing pilot light.

Q: Is this heater good for large pools?
A: Yes. The 400K BTU size is a strong fit for large residential pools, attached spas, and pool/spa combinations that need fast heat-up.

Q: Is professional installation recommended?
A: Yes. Gas pool heaters should be installed by a qualified professional to ensure proper gas, electrical, plumbing, venting, and safety setup.

Q: What should I verify before ordering?
A: Confirm fuel type, BTU sizing, gas supply, gas line sizing, electrical requirements, plumbing compatibility, venting requirements, installation clearances, and local code requirements.