Why is my consumer unit getting hot even though nothing is drawing much power?

It is understandable to be alarmed if your consumer unit feels warm or hot to the touch, especially when you are not running many appliances. The good news is that the cause is usually identifiable, but the bad news is that it almost always requires a qualified electrician to fix safely. Here is what is likely happening and what you can do right now. Why heat is generated even at low loads Electricity produces heat whenever it passes through resistance. In a healthy consumer unit, connections are tight and the resistance across every joint is extremely low, so very little heat is produced. When a terminal becomes loose, corroded, or was never tightened properly in the first place, that joint resists the flow of current and converts electrical energy into heat. This happens regardless of how much load is on the circuit. Even a few amps through a bad connection can raise temperatures to dangerous levels. What to look for safely Stand in front of your consumer unit and look carefully without touching anything inside. You are looking for: Discolouration or scorch marks on the plastic casing around individual breakers or the main switch. A burning smell, even faint or intermittent. Any breaker or RCD that feels noticeably hotter than the others when touched on the outside of the case. Meter tails or the main incoming cable feeling warm where they enter the unit. If you see any scorch marks or smell burning, treat this as an emergency. Do not delay. What you should not do Do not open the consumer unit yourself. The busbars and meter tails inside can carry live voltage even after switching off individual circuit breakers, and working on them without proper training and tools is extremely dangerous. Do not spray anything inside the unit. Do not assume the problem will go away on its own. When to call an electrician Call a registered electrician today if the unit is noticeably warm with low demand. Call immediately and consider calling 105 (the national power cut helpline, which can also assist in emergencies) or 999 if there is visible scorching, burning smell, or any sign of melting. This is a genuine fire risk and should not be left. A competent electrician will use an infrared thermometer and insulation resistance tester to locate the fault quickly. In most cases the fix is a retorqued or replaced terminal, though a badly damaged unit may need replacing entirely.