Marlo MGT / MFT Twin

Hard water breakthrough means the resin bed has exhausted before regeneration triggers. Check salt level and brine concentration, then verify the regeneration time clock setpoint against actual water usage.

Rising conductivity and sodium leakage from a DI column means the cation or mixed-bed resin is exhausted. Regenerate if the system is designed for it; replace the resin if it is a single-use or unregenerable mixed bed.

A stuck regeneration valve is almost always a failed drive motor, a stripped cam gear, or debris blocking the valve piston. Verify motor voltage, cam position, and piston movement before ordering parts.