Why are the Room Temperature panels not turning solid? L Why are the Room Temperature panels not turning solid? The PCM inside is NOT below its phase change temperature of 21.5°C/70.7°F. Make sure that the storage temperature is always below 20°C/68°F. Post navigationPrevious post: What is PCM?Next post: Why are the Fridge Temperature panels (PCM) not turning solid? Leave a Reply Cancel replyYou must be logged in to post a comment.