Product Overview

The Sta-Rite Max-E-Therm 400 Pool & Spa Heater | SR400LP is a high-performance propane gas heater designed for fast, efficient heating in residential pool and spa applications. With a powerful 400,000 BTU input, this heater is ideal for larger pools, spas, and pool/spa combination systems that need quick temperature recovery.

The Max-E-Therm series is known for its lightweight, compact design and durable Dura-Glas® rustproof enclosure, which helps protect the heater from outdoor conditions. Its digital controls, LED temperature readout, dual thermostat controls, and temperature safety lockout make operation straightforward and precise.

Designed for propane gas, 120/240 VAC electrical service, and 60 Hz operation, the SR400LP delivers dependable heating performance in a professional-grade package.

Ideal For

• Residential inground pools
• Pool and spa combination systems
• Fast spa heat-up applications
• Propane gas pool heating systems
• Replacing older gas pool heaters
• Outdoor pool equipment pads
• Approved indoor installations with proper venting
• Customers needing 400K BTU heating capacity
• Pool owners wanting a compact, lightweight heater
• Professional pool heater installations

Key Features

• 400,000 BTU input — delivers powerful heating for pools and spas.
• Propane gas operation — designed for homes and properties using LP gas service.
• High-performance Max-E-Therm design — built for fast heat-up and dependable operation.
• Digital control panel — provides clear temperature adjustment and system control.
• LED temperature readout — makes pool and spa temperature monitoring simple.
• Dual thermostat controls — allows separate pool and spa temperature settings when properly configured.
• Temperature safety lockout — helps prevent unauthorized or accidental temperature changes.
• Low NOx operation — designed for cleaner combustion and reduced emissions.
• Dura-Glas® rustproof enclosure — durable, weather-resistant cabinet built for outdoor environments.
• PMG burner technology — supports efficient combustion and reliable heating performance.
• Indoor/outdoor installation capable — approved applications must follow venting and code requirements.
• 120/240 VAC compatibility — supports standard pool heater electrical installation options.

Benefits

The Sta-Rite SR400LP Max-E-Therm heater gives pool and spa owners strong heating power in a compact, lightweight design. Its 400K BTU rating helps reduce wait time when heating a spa or bringing a pool up to temperature.

The Dura-Glas enclosure resists rust and outdoor wear, making it a strong choice for equipment pad installations. Digital controls make operation simple, while the dual thermostat system allows more convenient pool and spa temperature management.

For customers who need a propane heater with fast recovery, professional-grade construction, and trusted Sta-Rite/Pentair engineering, the SR400LP is a reliable high-output option.

Specifications

Included Components

• 1 × Sta-Rite Max-E-Therm SR400LP propane gas pool and spa heater
• Integrated digital control panel
• Electronic ignition system
• Dura-Glas heater enclosure
• Polymer manifold / header assembly
• 2" water connection components, depending on supplier packaging
• Manufacturer-supplied installation documentation

Propane gas line, gas regulator, shutoff valve, electrical wiring, bonding materials, venting components, plumbing valves, unions, check valves, and installation labor are sold separately unless specifically included by the supplier.

Installation Notes

This heater should be installed by a qualified pool professional, licensed gas technician, or licensed contractor as required by local code. Proper installation requires correct propane gas supply sizing, electrical wiring, bonding, grounding, water flow, plumbing layout, combustion air, venting if installed indoors, and startup testing.

Before installation, confirm that the fuel type is propane gas, the pool system can provide the required 40–120 GPM flow range, and the electrical supply is compatible with 120/240 VAC, 60 Hz operation.

Heaters may require factory modification or special setup for high-altitude installations. Always maintain water chemistry within recommended ranges to help protect the heat exchanger and preserve heater performance.

Customer-Facing Q&A

Q: What is the Sta-Rite SR400LP?
A: It is a Sta-Rite Max-E-Therm propane gas pool and spa heater rated at 400,000 BTU.

Q: What is the SKU?
A: The SKU is SR400LP.

Q: What is the UPC?
A: The UPC is 022315208278.

Q: What fuel type does this heater use?
A: This model uses propane gas / LP gas.

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

Q: What voltage does it require?
A: This heater is designed for 120/240 VAC, 60 Hz electrical service.

Q: Is this a natural gas heater?
A: No. This model is propane gas. Natural gas versions use different model numbers.

Q: Is this a Low NOx heater?
A: Yes. The Max-E-Therm SR400LP is designed as a Low NOx heater.

Q: What is the heat exchanger material?
A: This model uses a copper heat exchanger.

Q: What size water connections does it use?
A: It uses 2" water connections.

Q: What is the required flow range?
A: The listed flow range is approximately 40–120 GPM.

Q: Can this be installed indoors?
A: It may be installed indoors only when properly vented and installed according to code and manufacturer requirements.

Q: Should this heater be professionally installed?
A: Yes. Professional installation is strongly recommended because this heater requires proper gas, electrical, plumbing, venting, and safety setup.