Puresilk T4.0A Anti-Surge Ceramic Fuse | PS20LS PS25 PS30LS PS35 Hayward HWPS25 HWPS35

Common signs of a blown main fuse include the chlorinator showing no display, no output, or failing to power on at all despite the power supply being connected. To confirm, open the chlorinator control box (with power off) and visually inspect the fuse, or test it with a multimeter set to continuity mode. If there is no continuity, the fuse has blown and needs replacing.

T4.0A means the fuse is rated at 4 amps and is a time-delay (anti-surge or slow-blow) type. Anti-surge fuses tolerate brief current spikes — such as the inrush current when a chlorinator powers on — without blowing, while still protecting against sustained overcurrent faults. Always replace with the same rating and type.

A fuse that blows repeatedly usually indicates an underlying fault in the chlorinator — such as a short circuit on the main board, a faulty cell, or a wiring issue — rather than a faulty fuse. If replacing the fuse does not resolve the issue or the new fuse blows again, contact us on 02 9137 8914 for further diagnosis before replacing additional components.