Product Overview

The Pentair 474065 is a replacement heat-exchanger / tube-sheet coil assembly kit engineered for Pentair (and Sta-Rite) 400 K BTU HD series heaters built after January 12, 2009. This high-quality kit includes the cupro-nickel tube set, sealing O-rings, insulation kit, ignitor and adapter plates, providing full restoration of the water-heating core for these heavy-duty heater models. 

Ideal For

• Service professionals repairing a Pentair MasterTemp® / Max-E-Therm® 400K HD heater whose heat-exchanger has failed or is leaking.

• Pool owners with remaining heater cabinet, blower and wiring intact but needing core replacement to restore full performance.

• Installations looking to extend the life of an existing 400K HD heater rather than replacing the entire unit.

• Maintenance scenarios where corrosion, scale or tube damage require a true OEM replacement coil.

Key Features

• Cupro-Nickel Tube Sheet Coil Assembly – designed for excellent corrosion and salt resistance in HD series heaters.Complete Kit Format – includes tube set, sealing O-rings, insulation kit, adapter plates and necessary gaskets for full installation.Engineered for 400K BTU HD Models – compatible with models such as the MasterTemp 400HDNA / 400HD-LP manufactured after 1/12/09.

• OEM Fit & Finish – ensures mounting alignment, plumbing ports and internal geometry match factory design to maintain performance and warranty integrity.

• Cost-Effective Core Replacement – allows heater owners to refresh the key hydraulic section without full replacement of the entire heater unit.

Customer-Facing Q&A

Q: How do I know this kit fits my heater?
A: This kit is specifically for the 400K HD models manufactured after January 12, 2009 (new tube design). Confirm your heater’s model number, date code and that it is labeled “HD” or 400K series.

Q: What components are included in the kit?
A: The kit includes the coil/tube assembly, sealing O-rings, insulation kit, ignitor, blower adapter plate and gasket kits.

Q: Do I need to replace the entire heater if only the tubes are damaged?
A: Not necessarily — if the rest of the heater (blower, burner assembly, cabinet, wiring) is in good condition, replacing the heat-exchanger coil via this kit is a viable and cost-efficient repair.

Q: Is installation difficult?
A: It is a technical repair and should be performed by a qualified technician familiar with gas-heater maintenance, pressure testing and leak checks. Basic mechanical skill and safety protocol apply.

Q: What maintenance should follow installation of the new coil?
A: After installation, ensure proper combustion tuning, pressure testing, delay-start check, and monitor for leaks or abnormal pressure losses during initial operation.