Product Overview

The Pentair 77707-0209 is a genuine OEM set of manifold internals for 400,000 BTU Pentair pool and spa heaters. The internal manifold components direct water through the heat exchanger and keep flow balanced inside the heater. Replacing worn, warped or damaged internals restores proper water flow, efficient heat transfer and steady heater operation without replacing the full manifold.

⚠️ Important Purchase Notice

This is an internal heater component. Installation should be done 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 damaged or deteriorated manifold internals on a 400K Pentair heater.
• Heaters with uneven heating or flow problems traced to the manifold.
• Routine heater maintenance and water-system repairs.
• Pool heater service technicians.

Key Features

• Genuine Pentair OEM part, number 77707-0209.
• Sized for 400,000 BTU pool and spa heaters.
• Regulates internal water flow through the heat exchanger.
• Direct replacement for the original manifold internals.

Benefits

• Restores consistent, efficient heater performance.
• Supports proper heat exchange and water circulation.
• Lower-cost repair than replacing the full manifold or heater.

Compatibility

For 400,000 BTU Pentair pool and spa heaters, such as select MasterTemp 400 and Sta-Rite Max-E-Therm 400 models. Confirm your heater's model number, serial number and the part number in its parts list before ordering.

Installation or Upgrade Context

Turn off power, gas and circulation and let the heater cool. Open the manifold, remove the old internals, install the new 77707-0209 components with fresh seals, then reassemble. Restore water flow, check for leaks and test the heater.

What’s Included

• Pentair 77707-0209 manifold internal components for 400K heaters, as pictured

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

Will this fit my heater?

It is made for 400,000 BTU Pentair pool and spa heaters. Check your model and parts list for 77707-0209 before ordering.

Is this the whole manifold?

No. These are the internal components only; the manifold housing is sold separately.

Is professional installation recommended?

Yes. Heater internal components should be installed by a qualified pool professional.