Arrived on site to perform main on a unknown age system. Upon arrival spoke over with client and she stated she just moved in and wanted system inspected. She stated another company came out as was unable to service system due to the type of system and no access to work on system. Inspected and house only has heater and no Ac. Over all found system is a hydronic heater and we would not be able to not service this type of system due to the type and no access in attic for air handler. Client cycled heating and system was operational. Client is aware no work was performed just was able to educate client with the type of system it is. Client is aware why were unable to service this system. System is operational upon departure.