hot Tub Project controlling switchs

[Aethelflaed]

Hello,

I am working on a Hot tub Automation project. I Have the physical solid state relays and temperature sensor connected and working in Domoticz, I have successfully got the automatic temperature control working so that it keeps up to set temperature when unoccupied. What I am running into trouble with is adding more rules related to the 3 relays I am using. My set up is as follows:

Raspberry Pi Zero W, running Raspberry OS and Domoticz
Temp Sensor (1 wire)
Switch for Pump Hi Speed
Switch for Pump Low Speed
Switch for Heater
Virtual device Thermostat
Virtual Device Switch for tub Unoccupied

What I would like to add is an event(s):

so that only 1 speed of the pump (hi or low) can be turned on at a time
so that when occupied the heater with only turn on if the pump is running (either speed)

here are images of my dashboard and Blockly script so far.

dashboard.JPG (57.8 KiB) Viewed 374 times

blockly.JPG (57.44 KiB) Viewed 374 times

I have tried modifying the existing event and adding additional events, both of these has led to the working event not working.

Any help would be appreciated.