If your pool heater isn’t responding after adjusting the temperature, the issue might be simple—it’s off. In this guide, we walk you through how to properly operate your square model pool heat and cool pump and avoid common user errors.

Start by checking the digital display. If it says “OFF,” the unit won’t engage even if you set the temperature. Press the mode button, then press the plus (+) button to turn it on. Once it starts, the screen will return to the current water temperature.

Your square model heat/cool unit has three key operating modes:

• COL – Cool only

• HEAT – Heat only

• AUTO – Switches automatically between heat and cool based on your target temperature

Select your preferred mode and give the unit a few seconds to confirm and reset to the real-time temp reading. Now you’re ready to set your desired temperature and let the system maintain it.

These square-style heaters are reliable and efficient—if used correctly. Many first-time pool owners overlook the power-on step or forget to select the right mode, which leads to confusion when the system doesn’t react.