diff --git a/homeassistant/components/opentherm_gw/climate.py b/homeassistant/components/opentherm_gw/climate.py
index bcad621eb82..0b9cd1862be 100644
--- a/homeassistant/components/opentherm_gw/climate.py
+++ b/homeassistant/components/opentherm_gw/climate.py
@@ -84,6 +84,7 @@ class OpenThermClimate(ClimateEntity):
     _away_state_a = False
     _away_state_b = False
     _current_operation: HVACAction | None = None
+    _enable_turn_on_off_backwards_compatibility = False
 
     def __init__(self, gw_dev, options):
         """Initialize the device."""