Pentair Propane to Natural Gas Conversion Kit – 333 Model | Max-E-Therm | 77707-1421

Description

The Pentair Propane to Natural Gas Conversion Kit (77707-1421) is the OEM replacement conversion kit for the Sta-Rite Max-E-Therm 333 propane pool and spa heater — converting the burner system from liquefied propane gas (LP) to natural gas (NG) operation.

IMPORTANT: KIT CONTENTS
This listing is for a kit that includes items 3 & 4 from the Max-E-Therm 333 burner assembly. This kit is not included with the heater and must be ordered separately when a fuel-source conversion is required.

IMPORTANT: LICENSED PROFESSIONAL INSTALLATION REQUIRED
Gas and electrical heater components must be serviced by a licensed pool professional or qualified HVAC technician. Do not attempt to service gas or high-voltage components without proper certification. Converting a heater between fuel types involves gas supply connections and burner orifice changes — improper installation creates a serious fire and carbon monoxide hazard.

This kit provides the components required to convert the Max-E-Therm 333 burner system from propane to natural gas operation. Because propane and natural gas operate at different supply pressures and require different orifice sizing, a dedicated conversion kit is required — the heater cannot be converted by field modification of existing components.

Specifications

Fits Into

Compatibility is based on Pentair parts documentation and available OEM records. This is not an exhaustive list. For certainty, verify the part number in your equipment’s manual or on the original part itself before ordering.

Poolaroo Pro Tip

Before ordering, confirm your heater’s current fuel configuration by checking the rating plate on the heater cabinet — it will clearly state LP or NG. This kit is directional: LP to NG only. If you need to convert in the opposite direction (NG to LP), a different kit is required. Always have the conversion performed by a licensed professional and confirm your local gas utility requirements for natural gas supply pressure and line sizing before scheduling the work.