What indicates that an air compressor has a service problem in a building with steam radiators?

The indication that all the radiators would be in heating mode suggests that the air compressor associated with a steam radiator system is functioning properly. In a steam heating system, the purpose of the compressor is to manage and circulate the steam effectively throughout the system. If all radiators are giving off heat, it means that steam is reaching each radiator efficiently, which typically implies that there are no significant service problems with the compressor.

If the system were experiencing issues, one might expect to see varied temperatures across the radiators. For example, if some radiators are cold while others are hot, it would signal that steam is not being delivered evenly, pointing towards a potential malfunction of the compressor or another component of the heating system. The compressor's silence might also suggest a lack of operation, which is a problem. However, the consistent heating across all radiators indicates normal operation, making it the correct indication of the system's health in this context.