Refer to figure.
When warning lights associated with basic pitot/static heating systems in helicopters are illuminated, it generally indicates that either the heating element or the power supply has failed. The warning system is designed to alert the pilot when there is an issue with the heating system, which is critical for preventing ice accumulation on the pitot tube and static ports.

If only the heating element has failed, it could lead to ice buildup on the critical air data sensors, affecting the accuracy of airspeed and altitude indications. Similarly, if the power supply to the heating system fails, the heating element won't function correctly, and ice accumulation may occur.

Therefore, the warning lights are there to notify the pilot of any issues in either the heating element or the power supply, prompting them to take appropriate action to address the problem and ensure the accurate functioning of air data instruments.