All hydronic systems are governed by long-established and unchanging physical principles. Technicians who understand and apply these principles will often correctly identify underlying problems faster and more accurately.

Fundamentally, troubleshooting a hydronic heating system is a matter of verifying that processes are occurring in a pre-established sequence, and in an expected manner, starting at the fuel supply and tracing the process all the way to the level of comfort present in the building.

This section presents many of the commonly encountered symptoms in hydronic systems, provides one or more possible causes, suggests things to check and lists potential corrective actions.