At what temperature should my consumer unit be before I call the fire service?

Your consumer unit, sometimes called a fuse box, should feel slightly warm at most during normal use. If it feels genuinely hot to the touch, that is a warning sign you must act on immediately. In practical terms, the casing surface should sit no more than around 35 to 40 degrees above the surrounding room temperature. In a typical UK home where the room is around 20 degrees Celsius, that means the consumer unit surface should not exceed roughly 55 to 60 degrees Celsius. At that temperature you would not be able to hold your hand against it comfortably for more than a second or two. Signs that something is seriously wrong include: 1. The plastic casing feels genuinely hot, not just warm. 2. There is a burning or melting plastic smell near the unit. 3. You can see scorch marks, blackening, or discolouration on or around the unit. 4. You hear crackling, buzzing, or popping sounds from inside the unit. 5. Circuit breakers are tripping repeatedly for no obvious reason. 6. The lights flicker or you notice other unusual electrical behaviour in your home. If any of these signs are present, do not ignore them. Do not open the consumer unit yourself, as live components inside present a serious risk of electrocution and touching anything inside could make a fire worse. What you should do right now: 1. If the unit is visibly burning, smoking, or you smell burning and cannot locate the source, call 999 immediately and leave the property. 2. If it is hot but not yet smoking, turn off the main switch if it is safe to do so, then leave the property and call 999 to report a suspected electrical fire risk. 3. Once the fire service has confirmed the area is safe, call a registered electrician. Look for someone on the NICEIC or NAPIT register. 4. Do not restore power until a qualified electrician has inspected and confirmed the installation is safe. A consumer unit that runs hot is never a minor issue. It can indicate loose connections, overloaded circuits, or a faulty component, any of which can start a house fire. Always treat it as an emergency.