A plugged-in light or appliance flickers: why it happens

How to tell if the fault is in the device or in the socket

The quickest test is to plug something else into the same socket, such as a phone charger or a lamp you trust. If the second device also flickers or cuts out, the socket is the likely cause. If it runs fine, the fault probably sits with the first appliance or its cable.

Try the same appliance in a different socket, ideally on a different circuit or in another room. If the flickering follows the appliance, look at the appliance, its plug and its lead. If the flickering stays behind in that one socket, the socket is the problem.

Old appliances with worn internal wiring, a failing power supply, or a dimmer-type control can flicker on their own regardless of the socket. Kettles, heaters and anything with a motor draw a lot of current briefly, which can make a marginal connection show itself.

When a loose connection inside the socket is the cause

Sockets in Estonian flats are usually screw-terminal connections, and screws can work loose over years, especially if the socket was fitted quickly during a renovation or has had a lot of plugs pulled out of it. A loose wire makes intermittent contact, so the flickering often gets worse when you nudge the plug or lean on the wall near the socket.

This is common in older panel-house flats where the original sockets are decades old, and in sockets that carry something heavy like a washing machine or a kettle regularly. The fix is straightforward for an electrician: open the socket, check and re-tighten the terminals, and replace the socket if the contacts are worn or the plastic housing is scorched.

This is not a job to open up yourself if you are not confident working with a live circuit. Electrical work from us starts at 49 € an hour, and a socket replacement on its own is typically a fixed job from 35 €, which covers straightforward cases with easy access to the wiring.

When a hot socket means stop using it immediately

A socket that is warm or hot to the touch, that smells faintly of burning plastic, or that has a scorch mark or a slightly melted look around the pins, is not something to keep using while you wait for a convenient time. Heat means a poor connection is creating resistance, and resistance means the socket is heating up under load right now.

Unplug whatever is in it, switch off the circuit at the fuse box if you can identify it, and do not put anything back into that socket until it has been checked. This applies even if the flickering itself seems minor. Heat is the sign that separates an annoying fault from a fire risk.

If several sockets in the flat run warm at once, or the fuse box itself feels warm, treat it as urgent rather than something to check next weekend. We are on call around the clock for jobs like this within Tallinn and Harju county.

How to check whether the fault is in the plug or the appliance's cable

With the appliance unplugged, look at the plug itself: are the pins loose in the plastic body, is the plastic cracked, is there any blackening around the pin base? A plug that wobbles in your hand or feels warm after use is worth replacing on its own, which is a small job.

Flex the cable gently near the plug and near where it enters the appliance, the two points that take the most strain. If the flickering happens when you move the cable at one of these points, a wire inside has likely fractured from repeated bending. This is common with vacuum cleaners, kettles and anything that gets dragged around by its lead.

A cracked plug or a damaged cable is not something to tape up and keep using. Either point can be replaced, but if the appliance itself is old and the fault is inside its casing, replacing the appliance is often the more sensible choice than paying to repair it.

• Test the same appliance in a different socket or circuit
• Test a different device in the same socket
• Check if the plug's pins are loose or the casing is cracked
• Flex the cable near both ends and watch for flickering
• Feel the socket faceplate for warmth
• Look for scorch marks or a burning smell around the socket
• Note whether nudging the plug changes the flickering

What to do straight away and what can safely wait

If the socket is hot, smells of burning, or is visibly scorched, stop using it now and get it looked at rather than waiting. The same goes if the flickering comes with a burning smell from the appliance itself.

If the socket and appliance are both cool and the flickering is mild and consistent with one particular device, it is reasonable to swap the appliance's plug or retire the appliance and see if that resolves it before calling anyone out.

If you have ruled out the appliance and the fault clearly sits in the socket, that is worth booking rather than living with, since a loose connection tends to get worse, not better, with continued use. A call-out within Tallinn is 25 €, deducted from the bill if the work goes ahead.