Product Overview

The Pentair 77707-0441 is a genuine OEM gas orifice kit for 400,000 BTU Pentair MasterTemp and Sta-Rite Max-E-Therm pool and spa heaters running on propane (LP). The orifice meters gas flow to the burner, so it must match the heater's fuel type and BTU size. Use it to convert a 400K natural gas heater to propane or to service the gas train on a 400K propane heater.

⚠️ Important Purchase Notice

This is a gas-train component. Gas conversion and gas-train service must be performed by a qualified gas appliance technician following Pentair's instructions and local fuel-gas codes. Inspect the shipment upon arrival and report damage promptly.

Ideal For

• Converting a MasterTemp 400 or Max-E-Therm 400 heater from natural gas to propane.
• Servicing the gas train on a 400K propane MasterTemp or Max-E-Therm heater.
• Pool heater service technicians.

Key Features

• Genuine Pentair OEM part, number 77707-0441.
• Propane (LP) orifice sized for 400,000 BTU heaters.
• Fits Pentair MasterTemp 400 and Sta-Rite Max-E-Therm 400 heaters.
• Brass orifice with sealing O-ring.

Benefits

• Correct gas flow for clean, efficient propane combustion.
• OEM fit for a straightforward conversion or repair.
• Lets you run a 400K heater on propane where natural gas isn't available.

Compatibility

For 400,000 BTU propane MasterTemp and Max-E-Therm heaters. Natural gas heaters and other BTU sizes use different orifices. Confirm the heater model number, BTU rating and fuel type from the rating plate before ordering.

Installation or Upgrade Context

Shut off gas and electrical power before service. Replace the orifice following Pentair's conversion instructions, then leak-test all gas connections and verify proper gas pressure and combustion on startup.

What’s Included

• Propane gas orifice for 400K heaters
• Coil / tubesheet sealing
• O-ring kit
• Igniter gasket

Specifications

Warranty

Covered by Pentair’s manufacturer warranty, subject to Pentair’s applicable terms. Contact Pentair for warranty claim instructions; Pool Supply Depot can provide proof of purchase.

Customer Q&A

Which heaters does it fit?

Pentair MasterTemp 400 and Sta-Rite Max-E-Therm 400 heaters running on propane (LP).

Will it work on a natural gas or smaller-BTU heater?

No. It is the propane orifice for 400,000 BTU models only. Other fuel types and sizes use different orifice kits.

Can I install it myself?

Gas-train work should be done by a qualified gas appliance technician.