Product Overview

The Pentair MasterTemp ASME 400 Natural Gas Heater 460775 is a high-performance, ASME-certified pool and spa heater designed for demanding residential, semi-commercial, and commercial-style applications. With 400,000 BTUs of heating power, natural gas operation, and compact MasterTemp engineering, this heater delivers fast heat-up, dependable temperature recovery, and reliable performance for larger pools and spas.

The ASME version is built for applications where ASME-rated construction is required or preferred, making it a strong choice for apartments, condos, hotels, motels, community pools, high-end residential pools, and other heavier-use pool environments.

Ideal For

Large residential swimming pools

Pool and spa combination systems

Commercial-style pool and spa applications

Apartments, condos, hotels, motels, schools, parks, and community pools

Natural gas pool heating systems

Customers needing an ASME-certified heater

Replacing an existing 400K BTU ASME natural gas heater

Applications requiring fast heat-up and strong temperature recovery

Key Features

400,000 BTU natural gas heating performance

ASME-certified heater construction

Built for demanding residential and commercial-style pool applications

Compact MasterTemp cabinet design

Digital control panel for easy temperature adjustment

Rotating digital display for easier viewing and service access

Hot-surface / electronic ignition with no standing pilot

Low NOx certified heater design

Quiet operation for equipment pad installations

Manual gas shutoff for service convenience

Rust-resistant exterior cabinet

Designed for fast pool and spa warm-up

Compatible with many pool and spa automation systems

Benefits

The Pentair MasterTemp ASME 400 gives pool owners and commercial property operators powerful heating performance with ASME-rated construction. Its 400K BTU output provides fast pool heat-up and quick spa recovery, while the compact MasterTemp design helps save equipment pad space compared to many older heater designs.

The ASME configuration is ideal when local code, commercial use, property requirements, or project specifications call for an ASME-rated heater. Digital controls and diagnostic indicators help simplify operation and service, while the low NOx design helps meet modern emissions standards in many areas.

Specifications

Compatibility & Ordering Notes

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

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

Confirm whether ASME certification is required by local code, project specifications, commercial property requirements, or health department requirements.

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

This model is not for propane systems. For propane applications, use the correct propane ASME MasterTemp model.

Professional installation is strongly recommended.

Installed or used heaters may not be eligible for return.

Customer-Facing Q&A

Q: Is Pentair 460775 natural gas or propane?
A: Pentair 460775 is the natural gas version of the MasterTemp ASME 400 heater.

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

Q: What does ASME mean on this heater?
A: ASME refers to a certified construction standard often required for commercial or higher-demand pool applications. It may be required by code, project specifications, or property requirements.

Q: Is this heater good for commercial pools?
A: Yes. The ASME version is commonly used for commercial-style applications such as apartments, condos, hotels, motels, schools, parks, community pools, and high-end private pools.

Q: What is the barcode for Pentair 460775?
A: The barcode is 788379747558.

Q: Can this heater run on 120V or 240V?
A: Yes. MasterTemp heaters are designed for 120/240 VAC single-phase operation.

Q: Does this heater use a standing pilot light?
A: No. This heater uses hot-surface / electronic ignition and does not require a standing pilot.

Q: Is this the same as the standard MasterTemp 400 heater?
A: No. This is the ASME-certified version, intended for applications where ASME construction is required or preferred.

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

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