Product Overview

The Pentair 77707-0015 is a genuine OEM water system manifold kit for Pentair MasterTemp 300 (300,000 BTU) natural gas and propane pool and spa heaters. The manifold directs pool water through the heat exchanger, houses the bypass valve and holds the water pressure switch. This kit replaces a cracked, leaking or worn manifold and its key water-side parts to restore proper flow, bypass function and pressure-switch operation.

⚠️ Important Purchase Notice

Pool heater repairs involve water, gas and electrical systems. This kit should be installed by a qualified pool heater technician following Pentair's service instructions. Inspect the shipment upon arrival and report damage promptly.

WARNING: This product can expose you to chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.

Ideal For

• Replacing a cracked or leaking manifold on a MasterTemp 300 heater.
• Heaters with pressure switch or bypass problems traced to the manifold.
• Natural gas (300NA) and propane (300LP) models.
• Pool heater service technicians.

Key Features

• Genuine Pentair OEM part, number 77707-0015.
• Complete manifold kit for MasterTemp 300NA and 300LP.
• Includes the manifold bypass valve kit and water pressure switch.
• Includes O-ring kit, connector tube kit and zinc plug.

Benefits

• Stops leaks from a damaged manifold or worn seals.
• Restores correct water flow, bypass and pressure-switch operation.
• All the main water-side parts in one kit.
• Extends heater life when the rest of the unit is serviceable.

Compatibility

For Pentair MasterTemp heater water systems, models 300NA and 300LP. Other BTU sizes use different manifold kits. Confirm your heater's model number, serial number and existing part number before ordering.

Installation or Upgrade Context

Turn off power, gas and circulation, let the heater cool and relieve water pressure. Remove the old manifold, transfer any reusable parts such as the pressure relief valve, and install the new manifold with the supplied O-rings, bypass valve, pressure switch and connector tubes. Restore flow, check for leaks, confirm pressure-switch operation and test the heater.

What’s Included

• Manifold
• Coil/tubesheet O-ring kit
• Manifold bypass valve kit
• Water pressure switch
• Manifold O-ring
• Connector tube kit
• Zinc plug

Specifications

Warranty

Covered by a 60-day 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 this fit?

Pentair MasterTemp 300NA and 300LP heaters.

Is the water pressure switch included?

Yes. The kit includes the water pressure switch and the manifold bypass valve kit.

Will it fit a 200K, 250K or 400K MasterTemp?

No. Other heater sizes use different manifold kits.

Can I install it myself?

Professional installation by a qualified pool heater technician is recommended.