Dimension One spa not heating

[ACE402]

I have a Dimension One @Home Dream spa. It stopped heating and the temperature dropped down to 97 degrees.  I watched a few YouTube videos and most said the issue was the pressure control switch. I replaced the switch and refilled the tub and it was heating. It got up to 99 degrees and stopped heating. Any ideas what might be the problem?

Thank you,

David

[Steve Lockwood]

Could be a couple things. Is there an error code? first could be a clogged filter or a bad pressure switch. Since it seems it does heat some, it rules out a bad heater element.

[CanadianSpaTech]

Post photos of the control system circuit board and schematic on inside cover as well as the topside. Not a D1 expert by any means but with Balboa control systems they have a rest/ready mode. In rest mode spa will only heat to 99. In ready mode up to 104.