Product Overview

The Pentair Kit Htexch 400K HD Heaters Mfg | 474065 is a genuine Pentair replacement heat exchanger / tube sheet coil assembly kit designed for select 400K BTU heavy-duty pool and spa heaters.

This kit is commonly used on Pentair MasterTemp 400HDNA, MasterTemp 400HD-LP, and compatible Sta-Rite Max-E-Therm 400 HD heater applications. It is specifically referenced for heaters manufactured after January 12, 2009, using the updated tube design.

Built with cupro-nickel construction, this heat exchanger kit is designed for enhanced corrosion resistance and durability in demanding pool and spa heating environments. It helps restore proper heat transfer, water flow through the exchanger, and overall heater performance when the original heat exchanger is leaking, scaled, corroded, cracked, or damaged.

Ideal For

• Pentair MasterTemp 400K HD heater repairs
• Pentair MasterTemp 400HDNA natural gas heaters
• Pentair MasterTemp 400HD-LP propane heaters
• Sta-Rite Max-E-Therm 400 HD heater applications
• Replacing leaking heat exchangers
• Replacing corroded or scaled tube sheet coil assemblies
• Heavy-duty pool and spa heater service repairs
• Restoring heater efficiency and heat transfer
• Pool heater rebuilds
• Professional pool heater service technicians

Key Features

• Genuine Pentair replacement kit — OEM part designed for compatible Pentair and Sta-Rite 400K HD heater systems.
• 400K BTU HD heater compatibility — made for select heavy-duty 400K pool and spa heaters.
• Cupro-nickel construction — provides enhanced resistance to corrosion, erosion, and harsh pool water conditions compared with standard copper.
• Tube sheet coil assembly design — restores the heater’s internal water-to-heat transfer path.
• For updated heater design — commonly referenced for compatible heaters manufactured after January 12, 2009.
• Fits MasterTemp HD models — used with select MasterTemp 400HDNA and 400HD-LP heaters.
• Fits Max-E-Therm HD models — used with compatible Sta-Rite Max-E-Therm 400 HD heaters.
• Helps restore heater performance — improves heat transfer when the original exchanger is damaged or deteriorated.
• Service repair solution — replaces the heat exchanger without replacing the entire heater when the rest of the unit is serviceable.
• Professional-grade heater component — intended for qualified pool heater technicians.

Benefits

The Pentair 474065 heat exchanger kit helps bring compatible 400K HD heaters back to proper operating condition. A damaged heat exchanger can cause water leaks, poor heating, scale buildup, corrosion issues, overheating, or heater shutdowns.

Replacing the heat exchanger with the correct OEM kit helps restore heat transfer efficiency and protects the heater from continued operation with a compromised exchanger. The cupro-nickel construction is a strong choice for heavy-duty heater applications and pool environments where durability is especially important.

For pool professionals, the 474065 kit is a major service part for repairing compatible MasterTemp and Max-E-Therm HD 400K heaters manufactured after the January 2009 design update.

Specifications

Included Components

• 1 × Pentair 474065 heat exchanger / tube sheet coil assembly kit
• Coil sealing O-ring kit, where supplied by manufacturer packaging
• Manufacturer-supplied service components as packaged

Complete heater, burner tray, gas valve, control board, manifold parts not included in the kit, sensors, gaskets beyond supplied kit contents, plumbing fittings, electrical components, and installation labor are sold separately unless specifically included by the supplier.

Compatibility Notes

This kit is designed for select 400K BTU HD heater models only.

Common compatibility references include:

• Pentair MasterTemp 400HDNA
• Pentair MasterTemp 400HD-LP
• Pentair MT-400-NA-HD
• Pentair MT-400-LP-HD
• Sta-Rite Max-E-Therm SR400NAHD
• Compatible Sta-Rite Max-E-Therm 400 HD heater water system applications
• Heaters manufactured after January 12, 2009 with the updated tube design

Always confirm the heater model number, fuel type, serial number, manufacturing date, heat exchanger design, and official parts diagram before ordering. This kit is not universal for all MasterTemp, Max-E-Therm, or 400K heaters.

Installation Notes

This heat exchanger kit must be installed by a qualified pool heater technician or licensed professional. Heater repairs involve gas, electrical, water, combustion, and safety systems that must be serviced correctly.

Before installation, turn off gas supply, electrical power, and pool circulation equipment. Confirm the heater is cool and fully depressurized before disassembly.

After replacement, inspect and verify all seals, O-rings, water connections, sensors, gas connections, wiring, combustion chamber components, and water flow. The heater should be tested for leaks, proper ignition, correct temperature rise, and safe operation before being returned to service.

Water chemistry must be maintained within recommended ranges to protect the cupro-nickel heat exchanger and prevent premature scale, corrosion, or erosion damage.

Customer-Facing Q&A

Q: What is the Pentair 474065?
A: It is a Pentair heat exchanger / tube sheet coil assembly kit for select 400K BTU HD pool and spa heaters.

Q: What is the SKU?
A: The SKU is 474065.

Q: What is the UPC / GTIN?
A: The UPC / GTIN is 788379792039.

Q: What heater models does this fit?
A: It is commonly used with select Pentair MasterTemp 400HDNA, 400HD-LP, MT-400-NA-HD, MT-400-LP-HD, and compatible Sta-Rite Max-E-Therm 400 HD heaters.

Q: Is this for heaters made after January 12, 2009?
A: Yes. This kit is commonly referenced for compatible HD heaters manufactured after 1/12/2009 with the updated tube design.

Q: What material is the heat exchanger made from?
A: This kit is commonly listed as cupro-nickel.

Q: Is this for natural gas or propane heaters?
A: It can fit compatible HD natural gas and propane heater models when the exact model and part diagram match.

Q: Is this a complete heater?
A: No. This is a heat exchanger / tube sheet coil assembly kit only.

Q: Can this fix a leaking heater?
A: Yes, if the leak is caused by a failed heat exchanger and the heater model is compatible. Other components should also be inspected before repair.

Q: Can a homeowner install this kit?
A: No. This part should be installed only by a qualified pool heater technician or licensed professional.