Teledyne Laars Fusible Link R0012200

The Teledyne Laars R0012200 is the fusible link fitted to a broad range of Jandy Laars pool heaters, from the Series 2 units of the mid nineties through the Lite2 model LJ, the LX and LT, the LXi, the Hot Shot and the Legacy LRZE and LRZM.

What it is

A fusible link is a deliberately weak point in the control circuit. It is built to fail at a set temperature, and when the heater gets hotter than it should the link melts, the circuit opens and the heater stops. That is the whole design: it gives up so the heat exchanger, the burner tray and the surrounding cabinet do not.

Diagnosing a dead heater

A heater that will not fire at all, with no obvious fault on the control board, is often a blown link. It is a cheap part and an easy check on the parts breakdown for your model. What it is not is a fix on its own.

Find out why it opened

The link only goes when something has overheated the unit. Restricted water flow is the most common cause, from a dirty filter, a closed valve or an undersized pump. A scaled or soot fouled heat exchanger and a blocked or poorly drawing vent do the same. Sort the cause out first, or the replacement link will do exactly what the last one did.