problem: em 104 aqualine , my spa was giving me a false ready light on the panel and heater wouldnt work. solution: thermostat wires were cut at thermostat repaired and worked fine.

problem: s86 relay just replaced getting 120V in not outputing 120v to heater contactor.
Solution: parts dept person gave me wrong voltage relay it looks the same however it was for a 220v input. replaced with a 120v relay. heater working fine. something to keep in mind in case yours needs to be replaced.
thank u charger 1 .