I did a copy and paste of;
Balboa VS240R Part # 55035
Goes right to images of the Leisure Bay board and the Balboa heater.
The troubleshooting tree at the servicebalboa link is pretty straight forward for step by step on Sensor sync diagnostics and testing, just a few steps, ie: If this …. then do this or test this etc... takes you through a few steps, pictures or diagrams and all.
Always nice to hear a follow up down the road if or what worked out.
Best of luck !