The crucial task leading IPTV services to be successful is to ensure users’ quality of experience (QoE) better than, or at least comparable to the traditional cable/satellite TV. Among QoE measures, TV channel availability is of extreme importance. In this paper, we investigate how to improve the channel availability in IPTV systems with users zapping channels sequentially. Firstly, we present the negative influence on the channel availability, introduced by users’ sequential zapping behavior. Then, an intentional Switching Delay (iSD) admission control method, in combination with a 2-layered (base/enhancement layer) scalable video coding (SVC) scheme, is proposed to mitigate the impact. Thereafter, comprehensive simulation experiments demonstrate the potential of the iSD method, to significantly improve the channel availability, with only slightly degrading the average service delay of channel enhancement layers. Finally, our recently proposed TV channel access control (TCAC) scheme is integrated, aiming to further enhance the iSD method’s performance.