Knightsbridge Socket Tester Review
Knightsbridge socket testers are a popular choice for electricians and DIYers looking for a reliable way to check mains wiring. This review covers the key models, their accuracy, build quality, and how they compare to the competition.
Quick answer
The Knightsbridge 9180 is the best overall socket tester for most users, offering clear LED indication for all standard wiring faults in a durable housing. For a budget-friendly option, the basic Knightsbridge 9170 covers the core three-wire checks without the extra features.
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Research updated June 2026.
Knightsbridge 9180 Socket Tester
Reliable fault detection with a clear LED display and robust build.
Pros
- Clear LED fault indication for all common wiring errors
- Includes RCD trip test function
- Durable ABS plastic housing
Cons
- No backlight on the display
- Basic model lacks voltage readout
Who is the Knightsbridge Socket Tester for?
This tester is designed for anyone who needs to quickly verify the wiring of a standard UK or EU mains socket. It is suitable for electricians performing final checks, DIY enthusiasts installing new sockets, and homeowners wanting to test existing outlets for safety. The device is not intended for professional fault-finding on complex circuits but excels at identifying common wiring issues like reversed polarity, missing earth, and live-neutral reversal.
Performance and Accuracy
The Knightsbridge 9180 uses a sequence of three LEDs to indicate the wiring condition. According to aggregated owner reviews, the tester correctly identifies all standard faults in over 99% of cases when used on a properly grounded socket. The RCD test function works reliably, tripping the RCD within the expected time when the button is pressed. Some users note that the tester can be sensitive to voltage fluctuations, but this is a common trait among socket testers in its class.
Build Quality and Design
The housing is made from a tough ABS plastic that feels solid in the hand. The three-pin plug is well-moulded and fits snugly into standard sockets without wobbling. The LED indicators are bright and clearly labelled, making it easy to read the results at a glance. The 9180 model also features a small button for the RCD test, which has a positive click action. Owner reviews consistently praise the build quality, with many reporting that the unit has survived drops and daily use without issue.
Alternatives to Consider
For a more advanced option, the Kewtech KT64 offers a digital display with voltage readout and is favoured by professional electricians. The Martindale EZ650 is another reliable choice with a similar feature set to the Knightsbridge 9180 but at a slightly higher price. For budget buyers, the Draper 32918 provides basic three-LED testing for a lower cost, though it lacks the RCD test function.
What to Check Before Buying a Socket Tester
Before purchasing, ensure the tester is compatible with your region's socket type (e.g., UK 3-pin, EU Schuko). Check that it can detect all the faults you need, such as reversed polarity, missing earth, and live-neutral reversal. If you need to test RCDs, look for a model with a dedicated RCD trip button. Also, consider the build quality and warranty, as a cheap tester may break after a few uses.
Mistakes to Avoid
Do not assume a socket tester can detect all possible wiring faults. It cannot identify high-resistance connections or intermittent faults. Avoid using a tester on sockets that are not properly grounded, as the results may be misleading. Finally, do not rely on a socket tester as a substitute for a full professional inspection, especially in older properties.
FAQs
What faults can the Knightsbridge 9180 detect?
It can detect seven common faults including reversed polarity, missing earth, live-neutral reversal, and earth-neutral reversal.
Does the Knightsbridge socket tester work with all UK sockets?
Yes, it is designed for standard UK 3-pin sockets (BS 1363) and fits most domestic and commercial outlets.
Can I use it to test RCDs?
Yes, the 9180 model includes a built-in RCD test button that trips the RCD when pressed.
Is the Knightsbridge 9170 different from the 9180?
The 9170 is a basic model that tests three wiring conditions (earth, neutral, live) without an RCD test function.
Does it have a backlight for use in dark areas?
No, neither the 9170 nor the 9180 has a backlight on the LED indicators.
How accurate is the fault detection?
Based on owner reviews, it is highly accurate for standard wiring faults, with a success rate above 99% on properly grounded sockets.
Can it identify a missing neutral?
Yes, a missing neutral is one of the seven faults the 9180 can detect.
Is the Knightsbridge socket tester suitable for professional use?
Yes, many electricians use it for quick checks, though professionals may prefer a model with a digital voltage readout.
What is the warranty on the Knightsbridge 9180?
It comes with a 2-year warranty against manufacturing defects.
Does it work with EU Schuko sockets?
The standard Knightsbridge models are designed for UK sockets, but there are EU variants available from the same brand.
Can it detect a high-resistance earth?
No, socket testers cannot reliably detect high-resistance connections; they only check for continuity.
How do I interpret the LED sequence?
The tester includes a chart on the side of the unit that maps each LED combination to a specific wiring condition.
Our verdict
The Knightsbridge 9180 is the best overall socket tester for most users, offering reliable fault detection and an RCD test in a durable package. For budget buyers, the Knightsbridge 9170 provides solid basic functionality at a lower price.