Boiler control based on demand

Got my boiler system integrated into HA using ESPhome and relays (6 different zones, 10 total zone valves). I’ve got an automation that locks out the boiler based on my weather station outside temp @ 65 degrees F:

- id: '1580599005490'
  alias: Boiler Lockout
  description: ''
  - above: '-50'
    below: '65'
    entity_id: sensor.el_rancho_estudiante_temp
    platform: numeric_state
  condition: []
  - entity_id: switch.relay_channel_1_2
    service: switch.turn_on

The switch.relay_channel_1_2 is the boiler start/stop.

  - platform: generic_thermostat
    name: Family room
    heater: switch.relay_channel_2_2
    target_sensor: sensor.lumi_lumi_weather_12114a04_temperature
    min_temp: 62
    max_temp: 75

Turns on the zone valves for the family room.

My question is, along with the outdoor air temperature, is there any way to stop the boiler if none of the zones are calling? The boiler continues to run (it has its own loop, so it does have a “load”) but it seems unnecessary to have it run with no zones needing heat.