Found on many of the Chinese Arcadia Spas. We recommend you upgrade your controller to something better. These are known for heater leaks and other issues. These are obsolete and have been completely abandoned by the manufacturer. You will need to be replaced with a retrofit control system, as listed below.You will need to upgrade to the below controller:
Arcadia Spas Controller Spare Parts:
AEware in.ye-5 - No plumbing changes needed usually. Leads will need to be altered.