Hayward Heat Exchanger Assembly, H300FD

The Hayward FDXLHXA1300 is the genuine heat exchanger assembly for the Universal H-Series Low NOx H300FD pool heater. It is an exact replacement for the original, built to the same standard, and fits the H300FD without modification.

When it is the fix

Water inside the cabinet, rust streaking below the exchanger, or a heater that fires but has lost its heating performance all point to the exchanger. Replacing the assembly restores the heater rather than replacing the whole unit.

Before it goes in

The part is specific to the H300FD; other H-Series FD sizes use their own exchanger. And if the old exchanger failed early, check water chemistry before installing the new one. Low pH and high chlorine are what shorten an exchanger's life.