Why are the Fridge Temperature panels (PCM) not turning solid? L Why are the Fridge Temperature panels (PCM) not turning solid? The PCM inside is NOT below its phase change temperature of 4.5°C/40.1°F. Make sure that the storage temperature is always below 4°C/39.2°F. Post navigationPrevious post: Why are the Room Temperature panels not turning solid?Next post: Why are the Frozen Temperature panels not turning solid? Leave a Reply Cancel replyYou must be logged in to post a comment.