Pool and Spa
Questions about Pool Repair? Ask an Expert Online.
It sounds like the spa may be in Economy mode. This mode only allows the spa to heat during a filter cycle which is usually a two hour interval twice a day so it can appear that it is not heating. In most cases you need to change the mode from Ec to St. This is done by pressing the temp up button followed by the light button within 3 seconds of each other. Now the buttons and sequence can vary based on manufacturers so check your owners manual for proper method.