Pentair 77707-0015 Heater Manifold Kit 300/333K Mastertemp/Max-E-Therm

This kit is ideal for pool owners with 300K or 333K BTU heaters experiencing leaks, uneven heating, or visible manifold damage. It’s especially common in older units where thermal expansion and chemical exposure have weakened the original manifold.

Replacing the manifold restores balanced water flow, which improves heating efficiency and reduces stress on the heat exchanger. It’s a smart repair before minor leaks turn into major heater damage.

Best for:
300K & 333K BTU MasterTemp heaters
300K & 333K BTU Max-E-Therm heaters
Fixing internal heater water leaks
Preventative maintenance during heater service

Not ideal for:
200K or 400K BTU models (different manifold kits required)

Manifold kits vary by BTU size, and using the wrong one can cause alignment issues or improper sealing. The 77707-0015 is engineered specifically for 300K and 333K units, ensuring correct port alignment and pressure handling.

Pro Tip: If you’re replacing a manifold due to leaks, inspect the O-rings and check for scaling inside the heat exchanger while the heater is open. Addressing scale buildup at the same time helps extend the life of your new manifold and improves heat transfer efficiency.

In our field experience, catching manifold wear early prevents more expensive heat exchanger failures down the road.

Yes — this kit fits both compatible Pentair MasterTemp and Pentair Max-E-Therm 300K and 333K BTU models. Always confirm your heater’s BTU rating on the data plate before ordering to ensure correct fitment. Using the proper OEM manifold ensures proper sealing, alignment, and safe heater operation.