Product Overview

The Pentair MasterTemp HD 400 Natural Gas Heater 460805 is a heavy-duty, high-performance pool and spa heater designed for demanding residential and light commercial applications. With 400,000 BTUs of heating power, natural gas operation, and a durable cupro-nickel heat exchanger, this heater is built for fast heat-up, strong temperature recovery, and improved durability in harsher water conditions.

The MasterTemp HD series is a strong choice for pools and spas that experience heavy use, high flow conditions, or more challenging water chemistry compared to standard residential systems.

Ideal For

Large residential swimming pools

Pool and spa combination systems

Heavy-use pool and spa applications

High-end residential equipment pads

Light commercial pool applications

Natural gas pool heating systems

Customers wanting the added durability of cupro-nickel

Replacing an existing 400K BTU natural gas heater

Key Features

400,000 BTU natural gas heating performance

Heavy-duty HD MasterTemp design

Cupro-nickel heat exchanger for enhanced durability

Designed for harsher water conditions, high flow, and heavy use

120/240 VAC electrical capability

Digital control panel for easy operation

Hot-surface ignition with no standing pilot

Low NOx certified heater design

Compact cabinet for easier equipment pad placement

Quiet operation for residential and commercial-style equipment pads

Rust-resistant exterior cabinet

Compatible with many pool and spa automation systems

Benefits

The Pentair MasterTemp HD 400 provides powerful heating performance with added durability where a standard heater may not be the best fit. Its cupro-nickel heat exchanger is designed to better handle demanding pool environments, including high flow applications, heavy usage, and tougher water chemistry conditions.

With 400,000 BTUs of output, this heater delivers fast pool heat-up and quick spa recovery. The compact MasterTemp design also makes it easier to install or replace on many existing equipment pads while still offering strong heating power.

Specifications

Compatibility & Ordering Notes

Confirm this is the correct natural gas model before ordering.

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

Confirm that the HD cupro-nickel model is the correct choice for your installation.

Check gas line size, gas supply, electrical requirements, plumbing layout, venting requirements, equipment pad clearances, and local code requirements.

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

Professional installation is strongly recommended.

Installed or used heaters may not be eligible for return.

Customer-Facing Q&A

Q: Is Pentair 460805 natural gas or propane?
A: Pentair 460805 is the natural gas version of the MasterTemp HD 400 heater.

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

Q: What makes the HD model different from a standard MasterTemp 400?
A: The HD model includes a cupro-nickel heat exchanger, which is designed for added durability in more demanding pool environments.

Q: Is this heater good for large pools?
A: Yes. The 400K BTU size is a strong option for large residential pools, attached spas, and systems that need fast heat-up or quick temperature recovery.

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

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

Q: Is this model automation compatible?
A: Yes. It can connect with compatible pool and spa automation systems.

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

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