Hayward H-Series System On/Off Switch CZ/HM2/H-Series, CHXTSW1930

The Hayward CHXTSW1930 is the system on/off switch used on ComforZone CZ, HeatMaster HM2 and H-Series pool heaters.

What it does

This is the switch on the control panel that puts the whole heater in or out of service. Everything downstream of it, the display, the control logic and the firing sequence, waits on this one contact. That makes it a small part with an outsized effect: when it fails, a perfectly healthy heater looks completely dead.

Before you buy a control board

A heater that shows nothing at all with good supply voltage at the terminals is worth testing at the switch first. Switches on equipment that sits outdoors for years give up long before the electronics do, and this is far cheaper than the board people usually suspect.

Safety

Isolate the heater at the breaker before the control compartment is opened. There is line voltage inside, and the on/off switch being off is not the same as the heater being isolated.