WARNINGS:

240/110 VAC power is hazardous. This is NOT a project for beginners.

Pool heating should always be turned OFF while the pool heat is running, as there is a possibility of scalding water on startup.

LM35DZ Temperature sensor information:

Search ebay for "Waterproof Digital Thermal Probe LM35DZ Temperature Probe".   These probes are inserted into the PVC pump lines using a 8mm pool solar manifold grommet.

AC power notes:

The project is powered by the same AC supply used for the pool pump, but uses a commercial 12V wall wart built into the box to provide the required 12C DC.    A relay is used to switch the pump on and off, and all AC based components are in a separate compartment of the controller.