A maintenance system for use with at least one HVAC system including at least one indoor unit, at least one outdoor unit and at least one communication line extending therebetween, said system including: at least one remotely accessible server including at least one processor and at least one memory unit; at least one probe operatively connectable to the at least one communication line of the at least one HVAC system and configured to acquire operational data transmitted along the at least one communication line ; and a communication module operatively connected to the at least one probe and configured to transmit said operational data acquired to said at least one remotely accessible server , characterised in that the at least one probe is a packet analyser configured to intercept and log operational data in the form of packets exchanged along the at least one communication line , the at least one remotely accessible server is programmed to: receive and store said operational data acquired for said at least one HVAC system ; identify any operational anomalies by analysing said operational data; responsive to an operational anomaly being identified, designate a tiered maintenance status for said at least one HVAC system selected from a minor maintenance required designation and a major maintenance required designation; and transmit a corresponding tiered maintenance request selected from a minor maintenance request and a major maintenance request to a technician based on the tiered maintenance status designated for said at least one HVAC system . at least one remotely accessible server including at least one processor and at least one memory unit; at least one probe operatively connectable to the at least one communication line of the at least one HVAC system and configured to acquire operational data transmitted along the at least one communication line ; and a communication module operatively connected to the at least one probe and configured to transmit said operational data acquired to said at least one remotely accessible server , characterised in that the at least one probe is a packet analyser configured to intercept and log operational data in the form of packets exchanged along the at least one communication line , the at least one remotely accessible server is programmed to: receive and store said operational data acquired for said at least one HVAC system ; identify any operational anomalies by analysing said operational data; responsive to an operational anomaly being identified, designate a tiered maintenance status for said at least one HVAC system selected from a minor maintenance required designation and a major maintenance required designation; and transmit a corresponding tiered maintenance request selected from a minor maintenance request and a major maintenance request to a technician based on the tiered maintenance status designated for said at least one HVAC system . receive and store said operational data acquired for said at least one HVAC system ; identify any operational anomalies by analysing said operational data; responsive to an operational anomaly being identified, designate a tiered maintenance status for said at least one HVAC system selected from a minor maintenance required designation and a major maintenance required designation; and transmit a corresponding tiered maintenance request selected from a minor maintenance request and a major maintenance request to a technician based on the tiered maintenance status designated for said at least one HVAC system . <EOS>