Tell me how you'd check the power-assisted steering is working before starting a journey.
If the steering becomes heavy, the system may not be working properly. Before starting a journey, 2 simple checks can be made.
Gentle pressure on the steering wheel, maintained while the engine is started, should result in a slight but noticable movement as the system begins to operate. Alternatively turning the steering wheel just after moving off will give an immediate indication that the power assistance is functioning.