We present a model that solves the abundance discrepancy problem for NGC 6210. The model proposes a high abundance of CNONe elements that lowers the temperature of the central parts of the nebula. The colder gas model reproduces the observed intensity of the strong [N ii] and [O iii] emission lines, and increases the predicted weak recombination lines towards their observed values. We examine how the usual nebular diagnostic line ratios depend on model abundances.