An increase in CO 2 /H + is a major stimulus for increased ventilation and is sensed by central chemoreceptor neurons in various nuclei of the brainstem. Of particular importance in the study of central chemoreception are the cellular factors that determine the increased firing rate response of these neurons to acidotic conditions. A multiple factors model proposes that a set of signals and ion channel targets results in the increased firing rate response when chemoreceptors are stimulated with hypercapnic acidosis. We have developed a mathematical model for a mammalian chemoreceptor to understand the interplay between the underlying pH‐sensitive ionic currents when stimulated with increased CO 2 /H + . It consists of an ionic membrane model of the Hodgkin‐Huxley type with several CO 2 /H + ‐sensitive currents that makes the neuron fire at frequencies between 0.4 and 4 Hz. The currents included in the model are: fast Na+, delayed rectifier K + , inward rectifier K + , TASK, A‐type K + , L‐type Ca 2+ , BK‐type Ca 2+ ‐activated K + , and a hyperpolarization activated current. We also included a background current to take account of ion flows driven by pumps and regulatory mechanisms that are not represented as independent currents in the model. We performed a sensitivity analysis for the pH‐sensitive currents to study the effect of their conductance on the firing frequency of the neuron and to determine which currents are playing the major role in the chemosensitive response. For each current, a sensitivity factor was calculated as the rate of change of the firing frequency with regard to conductance in normocapnic conditions. The analysis revealed a higher sensitivity for TASK, L‐type Ca 2+ , and background currents, with sensitivity values between −3.3 and −1.5, compared with other currents with sensitivity absolute values below 0.05. These results indicate that a small inhibition of these currents results in a significant increase in the firing rate of the neuron compared with other channels, which would result in an increased chemosensitive response with the appropriate stimulus. These findings support the multiple factors model of chemosensitive signaling and postulate TASK and Ca 2+ currents as primary sensors. We also highlight the contribution of unknown mechanisms like acid sensitive pumps and pH regulatory mechanisms, which might be responsible for the unexpectedly high sensitivity of the background current in this model.