Compatibility with Versatile Thermostat & DIYLESS

[discipleofnagash]

Hi, I'm looking at SAT because currently my boiler is operating in an on/off mode and I want to use OpenTherm to get modulation control (I have an Ideal C35 combi boiler).

My two main questions are:

• How (and can?) this work with my multi-room Versatile Thermostat setup, I have 13 climates that are managed in Vtherm over valve, which is using aquara sensors in the rooms and then controlling my shelly TRVs. They are in auto-tpi learning mode so try and limit overshooting to handle everything to do with the climate of the room. I also have the power configured for my climates based on the radiator wattages, so effectively I know the house demand based on wattage x valve opening. How would this be configured with SAT so that SAT controls the boiler to try and be the most efficient based on demand/flow return temp etc?

• Second question is I have this OpenTherm controller: https://diyless.com/product/opentherm-thermostat?
  srsltid=AfmBOopd2tA1ilbJCwQQKUP36MkUXY06x87oJzbn6xpHs9q6hHsuOeE8 - I was advised this would work, but I've seen another comment back from 2024 that this doesn't work with DIYLESS? Can you advise if this it the case or is has this changed?

Thanks!

EDIT: I came across this comment in another discussion:

If you have a multi-room installation, you can update to the latest develop version, enable the Dynamic Minimum Setpoint (Experimental) option, and then select your boiler’s flow water temperature in the General Settings. This mode “senses” the flow water temperature and adjusts the control setpoint accordingly in multi-room environments.

Would this be the recommended approach for me?

[sergeantd83]

You can run the latest SAT version ( 4.2.1 ).

[discipleofnagash]

Does this solve both my problems?

[sergeantd83]

The answer for your first question is here. You will understand how SAT works.
Regarding your second question, yes it will work with the latest 4.2.1 version

[tbrasser]

I also use this setup (only esphome opentherm)

sat config: each vtherm as room climate, no main trv/thermostat

Aterwards I created another vtherm over climate over the sat created climate entity (and configured it as no-auto-regulation and to follow underlying temp changes)

So for control now I have 1 vtherm climate per room. I don't use versatile thermostat's central boiler functionality (all of that is handled by sat comfort mode)

[repa6]

Could you post your working esphome yaml please?

[tbrasser]

Could you post your working esphome yaml please?

this is the unique part (outside of normal api/ota/logger/wifi/etc):

substitutions:
  name: opentherm
esp32:
  board: mhetesp32minikit
  framework:
    type: esp-idf
esphome:
  name: ${name}
  friendly_name: "${name}
opentherm:
  in_pin: GPIO19
  out_pin: GPIO18
  ch_enable: true
  dhw_enable: true
number:
  - platform: opentherm
    t_dhw_set:
      name: t_dhw_set
      step: 1
      restore_value: true
      initial_value: 45
    t_set:
      name: t_set
      restore_value: true
      initial_value: 10
      step: 0.1
    max_t_set:
      name: max_t_set
      step: 1
      restore_value: true
    max_rel_mod_level:
      name: max_rel_mod_level
      min_value: 0
      max_value: 100
      step: 1
      initial_value: 100
      restore_value: true
sensor:
  - platform: opentherm
    rel_mod_level:
      name: rel_mod_level
    device_id:
      name: device_id
    t_boiler:
      name: t_boiler
    t_ret:
      name: t_ret
    max_capacity:
      name: max_capacity
    min_mod_level:
      name: min_mod_level
    t_dhw_set_lb:
      name: t_dhw_set_lb
    t_dhw_set_ub:
      name: t_dhw_set_ub
    t_exhaust:
      name: t_exhaust
    ch_pressure:
      name: ch_pressure
    t_dhw:
      name: t_dhw
    fan_speed:
      name: fan_speed
    fan_speed_setpoint:
      name: fan_speed_setpoint
    flame_current:
      name: flame_current
    burner_starts:
      id: burner_starts
      entity_category: diagnostic
    ch_pump_starts:
      name: "Number of starts CH pump"
      entity_category: diagnostic
    dhw_pump_valve_starts:
      name: "Number of starts DHW pump and valve"
      entity_category: diagnostic
    dhw_burner_starts:
      name: "Number of starts burner during DHW mode"
      entity_category: diagnostic
    burner_operation_hours:
      name: "Number of hours that burner is in operation"
      entity_category: diagnostic
    ch_pump_operation_hours:
      name: "Number of hours that CH pump has been running"
      entity_category: diagnostic
    dhw_pump_valve_operation_hours:
      name: "Number of hours that DHW pump has been running or DHW valve has been opened"
      entity_category: diagnostic
    dhw_burner_operation_hours:
      name: "Number of hours that burner is in operation during DHW mode"
      entity_category: diagnostic
    max_t_set_ub:
      name: "Upper bound for adjustment of max CH setpoint"
      entity_category: diagnostic
    max_t_set_lb:
      name: "Lower bound for adjustment of max CH setpoint"
      entity_category: diagnostic
    t_dhw_set:
      name: t_dhw_set
      entity_category: diagnostic
    max_t_set:
      name: "Maximum allowable CH water setpoint"
      entity_category: diagnostic
    opentherm_version_device:
      name: "Version of OpenTherm implemented by device"
      entity_category: diagnostic
    device_type:
      name: device_type
      entity_category: diagnostic
    device_version:
      name: device_version
      entity_category: diagnostic
binary_sensor:
  - platform: opentherm
    flame_on:
      name: flame_on
    ch_active:
      name: "Boiler Central Heating active"
    dhw_active:
      name: dhw_active
    fault_indication:
      name: "Boiler Fault indication"
      entity_category: diagnostic
    diagnostic_indication:
      name: "Boiler Diagnostic event"
      entity_category: diagnostic
    electricity_production:
      name: "Boiler Electricity production"
    dhw_present:
      name: "Boiler Domestic Hot Water present"
      entity_category: diagnostic
    control_type_on_off:
      name: "Boiler Control type on-off"
    water_filling:
      name: "Boiler Water filling"
      entity_category: diagnostic
    heat_mode:
      name: "Boiler Heat mode"
      entity_category: diagnostic
    dhw_setpoint_transfer_enabled:
      name: "Boiler DHW setpoint transfer enabled"
    max_ch_setpoint_transfer_enabled:
      name: "Boiler Max CH setpoint transfer enabled"
    dhw_setpoint_rw:
      name: "Boiler DHW setpoint RW"
    max_ch_setpoint_rw:
      name: "Boiler Max CH setpoint RW"
    service_request:
      name: "Boiler Service request"
    lockout_reset:
      name: "Boiler Lockout reset"
    low_water_pressure:
      name: "Boiler Low water pressure"
    flame_fault:
      name: "Boiler Flame fault"
    air_pressure_fault:
      name: "Boiler Air pressure fault"
    water_over_temp:
      name: "Boiler Water over temperature"
switch:
  - platform: opentherm
    ch_enable:
      name: ch_enable
      restore_mode: RESTORE_DEFAULT_ON
    dhw_enable:
      name: dhw_enable
      restore_mode: RESTORE_DEFAULT_ON

[machine-bit]

I have a similar setup, 14 zones of Versatile connected to 14 Heatmister Neo, mainly using veratile for the central boiler and the activation threshold. But If I can get the SAT working without the boiler cycling when just a loop or two of UFH is operating I might sack off the central boiler.

At the moment I cannot get past this

[machine-bit]

@discipleofnagash / @tbrasser how are you getting on with this? I am trying to achieve a heatmister Neo plus Vertitile plus SAT to control the flow temps. How have you configured SAT with your multi zone setup? I feel like SAT needs to have a full picture of the combined demand for heat to work out what it needs to do?

cheers