If your spa temperature is low, first check the thermostat to see if it has been turned down or set to low heat range. Adjust the thermostat to desired temperature or set to high heat range. Another common reason for your spa temperature to be low is because the high limit sensor has tripped. Press any button on your control panel to reset the system. If neither of the above steps works, your heating system may be defective. Contact your authorized Bullfrog Spas Dealer for further diagnosis.