Domakihub How to Test a Socket with a Socket Tester (and When to Call an Electrician)
A quick plug-in check that every property owner in Greece should know.
Reviewed by Domakihub home & decor pros · 2026-06-23 · 4 min read
A socket tester is a small, inexpensive plug-in device that lights up to tell you whether an outlet is wired correctly — no tools, no exposed wires, no licence required to use one. The video above walks through the process visually; the steps below give you the full picture so you know exactly what the indicator lights mean and what to do if a fault shows up. Whether you manage a home in Athens, a holiday rental in Crete, or a boutique hotel on Santorini, a two-minute check before guests arrive can prevent appliance damage and flag wiring faults that a qualified electrician should fix.
What a Socket Tester Does — and What It Cannot Do
A socket tester (sometimes called a plug-in outlet tester) carries three indicator LEDs. By lighting up in different combinations, it tells you whether the Live, Neutral, and Earth conductors are present and connected in the correct positions. The most common faults it catches are missing earth, Live and Neutral reversed, Live and Earth reversed, and an open circuit on one of the conductors.
What the tester cannot do is measure insulation resistance, detect a high-resistance earth (which can pass the LED test yet still be dangerous under load), or confirm that a circuit is protected by an RCD/GFCI of the correct rating. For a full Periodic Inspection Report — legally required for rental properties in Greece under ELOT HD 384 — you need a licensed electrician with calibrated test equipment.
Understanding Greek Wiring and Socket Types
Most properties in Greece use the Schuko standard (Type F, CEE 7/4): a round two-pin socket with two earth clips on the sides. Older buildings — especially pre-1980 island properties — sometimes have ungrounded two-pin sockets (Type C) with no earth at all. A socket tester designed for Schuko outlets will correctly indicate a missing earth on these old sockets, which is useful information but not itself a fix.
If your property has a mix of socket types or you are not sure which standard applies, have an electrician survey the installation before using testers or adapters. Adapters that downgrade from Schuko to two-pin can defeat the earth connection and create a shock hazard — avoid them for anything other than low-power, double-insulated devices.
How to Test a Socket Step by Step
- 1
Read the indicator chart before you start
Every socket tester comes with a legend — usually printed on the tester body or in a small leaflet — that maps LED combinations to fault codes. Read it before you begin so you can interpret results on the spot. Common designations are three LEDs labelled or colour-coded for Earth (E), Neutral (N), and Live (L). Photograph the chart with your phone if the print is small.
- 2
Turn off or unplug anything connected to the socket
Remove any device that is plugged into the socket you want to test. You do not need to switch the circuit off at the consumer unit — the tester is designed to be inserted into a live socket — but having a load on the socket at the same time can sometimes affect very cheap testers. Safety first: never touch the tester pins directly.
- 3
Plug the tester firmly into the socket
Push the tester squarely into the socket until it seats fully. On Schuko sockets the two round pins engage first, then the earth clips make contact on the sides. Wait one to two seconds for the LEDs to stabilise. Do not force the tester if it does not seat — this may indicate a damaged or non-standard socket.
- 4
Read the LED pattern and compare it to the chart
A correct wiring result on most testers is two LEDs lit (often the two rightmost ones, labelled L and N or similar). All three lit, only one lit, or none lit each indicate a different fault. Write down the socket location and the result as you go around the property — a spreadsheet or a notes app works well for holiday rental inventories.
- 5
Act on the results: self-fix vs. call an electrician
If all sockets show correct wiring, no immediate action is needed — keep a record and retest annually or after any renovation. If the tester shows a missing earth, reversed Live/Neutral, or open circuit on any conductor, stop using the socket, label it out of service, and contact a licensed electrician. These are not issues a non-qualified person should attempt to fix: re-wiring a socket involves working inside a live consumer unit and is regulated work in Greece. A Domakihub-vetted electrician can fix a faulty socket, run a full periodic inspection, and issue the required paperwork for rental licences.
Rather have a pro handle it?
Get a vetted electrician pro in your city — one number, booked in EN/EL/DE.
FAQ
- Can I use a UK or US socket tester in Greece?
- No — pin geometry differs. Greece uses Schuko (Type F) outlets. You need a tester with Schuko-compatible pins. Many electricians' testers sold on Amazon EU or in Greek electrical wholesalers are Schuko-ready; check the packaging before buying.
- My tester shows a fault on every socket in one room. What does that mean?
- A systematic fault across an entire circuit usually points to a wiring error at the distribution board or junction box serving that circuit — for example, a Neutral and Live swapped at the source, or a broken earth conductor for the whole ring. This is not a socket-by-socket repair; it requires an electrician to trace and correct the circuit from the consumer unit.
- How often should I test the sockets in a holiday rental?
- Test at the start of each rental season and after any building work or appliance installation. Greek law requires a Periodic Inspection Certificate (Υπεύθυνη Δήλωση Ηλεκτρολόγου) for rental property registration; the interval depends on the type of property, but every five to ten years is the typical requirement. A socket tester check between professional inspections helps you spot new faults early and keep guests safe.