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This topic is intended to collect facts about how different thermostats work with the OTGW, to be consulted by people wanting to purchase a thermostat.

Please only post information here. Questions should go to some other topic. I will combine the information in one post per thermostat type.

Features:

• Supports setpoint override to .01 degrees (display rounded to .5 degrees).
• Supports both temporary and constant setpoint override.
• Supports clock adjustment (time and day of week only).
• Supports display of outside temperature provided via opentherm.

The Hometronic icon is displayed when a remote setpoint override is active.

Features:

• Supports setpoint override (requires firmware version 19 or higher).
• Supports both temporary and constant setpoint override, but needs up to 12 minutes to learn which one was requested.
• Supports clock adjustment only at startup.
• Supports display of outside temperature.
• Can take advantage of Smart Power from the gateway.

Remote setpoint override is disabled by default and has to be enabled via the menu. This is only accessible in extended menu mode:
Main menu -> Settings -> Installer -> Remote input -> Allow (Dutch: Hoofdmenu -> Instellingen -> Installateur -> Externe ingang -> Toestaan)
It is advised to switch off comfort correction as it may cause the room setpoint to deviate enough from the requested value for the OTGW to cancel the override:
Menu -> Settings -> System -> Temperature -> Comfort corr. (Dutch: Menu -> Instellingen -> Systeem -> Temperatuur -> Comfort corr.)

Features:

• Supports constant setpoint override only with a resolution of .2 degrees.
• Supports display of outside temperature.

Features:

• Supports constant setpoint override only.
• The T87M1003 constantly sends DHWenable. The T87M1011 has a button to manually control DHWenable.

Features:

• Supports setpoint override, but only with a resolution of 1 degree.
• Supports display of outside temperature.
• Does not support clock adjustment
• Supports ventilation.
• Supports cooling.
• Supports display of CO2 value.
• Supports display of Relative humidity value.

To use the Remote setpoint override, the TELE function must not be enabled.
The Hometronic icon (a "H" with a 'roof') is displayed when a remote setpoint override is active.

Features:

• Supports setpoint override, but only with a resolution of 1 degree.
• Supports display of outside temperature.
• Does not support clock adjustment.
• Supports ventilation.
• Supports cooling.
• Supports display of CO2 value.
• Supports display of Relative humidity value.

Remote setpoint override must be enabled via the menu. The TELE function must not be enabled at the same time.
The Hometronic icon (a "H" with a 'roof') is displayed when a remote setpoint override is active.

The CMT957M1011 is actually a CMS927B(1015) control unit combined with a R8810A1018 OT relay box. (Thanks to D_Hailsham for figuring out and sharing these details.)

Features:

• Does not support setpoint override
• Always reports the room temperature as 20 degrees

• Supports setpoint override. Resolution 0.1°C
• display has 0.5°C resolution
• Shows square symbol in top right hand corner of display in override mode (undocumented symbol AFAIK)
• Provides 5°C minimum temperature setting for 'away' mode or similar
• Nodo Shop OT gateway works fine, allows scheduling and away detection from HASS

• Supports setpoint override, by HS4 plugin from Bernold OTGW plugin (Resolution 0.5°C)

• Nodo Shop OT gateway works fine

fanagolo wrote: ↑Wed Feb 01, 2023 11:23 pm

• Supports setpoint override. Resolution 0.1°C
• display has 0.5°C resolution
• Shows square symbol in top right hand corner of display in override mode (undocumented symbol AFAIK)
• Provides 5°C minimum temperature setting for 'away' mode or similar
• Nodo Shop OT gateway works fine, allows scheduling and away detection from HASS

Extra information: If this is connected directly to an older OpenTherm boiler, it might not work (because those don't supply power over the OpenTherm terminals). When connected via the OTGW, it does work.

If with an older Opentherm boiler you mean a boiler that only supports OT/- aka OpenTherm/Lite, then your remark probably applies to most thermostats. I have not encountered a thermostat that does OT/-. But the OTGW also won't work with such a boiler.