The application of the ideal associated solution approximation to calorimetric investigations of hydrogen bonding in binary solutions is considered from the viewpoint of solution thermodynamics. A simple model of nonideality is introduced to accommodate nonchemical contributions to the excess enthalpy of a binary solution containing a hydrogen-bonded complex. Application of the model to the chloroform + triethylamine system appears to be quite reasonable, and shows that relatively small contributions of nonideality can lead to large errors in hydrogen bonding parameters determined with the ideal associated solution approximation.