Before you call for repair service, check your. Monday - friday from 8am to 5pm. The thermal actuator twa range is used with electrical on/off-controls to activate several types of valves and floor heating manifolds the actuator is equipped with a visual position indicator to show the open or closed position of the valve the twa-actuator can be connected to the ra, ravl and rav valves from danfoss furthermore versions for valves with m30x1.5 connection are.