<p>A system and computer-implemented method for monitoring and diagnosing anomalies in a wheel-space of a gas turbine is implemented using a computer device coupled to a user interface and a memory device and includes storing a plurality rule sets in the memory device, the rule sets relative to the wheel-space, the rule sets including at least one rule expressed as a relational expression of a real-time data output relative to a real-time data input, the relational expression being specific to a temperature of the wheel-space. The method also includes receiving real-time and historical data inputs from a condition monitoring system associated with the gas turbine, the data inputs relating to sources providing heat to the wheel-space and estimating a wheel-space temperature value using the inputs relating to a temperature of the wheel-space.</p>
