Independent comparisons. We may earn from shop links. More info

How to use a voltage tester screwdriver

Updated: October 2026

You are at a UK socket with a neon screwdriver. How to use a voltage tester screwdriver is three beats: prove the lamp on a known live point, touch the point you care about, then prove the lamp again. A glow means you treat that point as live. A dark lamp means the neon did not strike. It does not mean the conductor is dead. The listings are on the [voltage tester screwdriver comparison](/hub/hand-tools/voltage-tester-screwdriver). The Products Compared editorial team used the DIY FAQ neon note and HSE GS38. There is no laboratory test. A qualifying purchase through our links can earn a commission at no extra cost to you.

You are at a UK socket with a neon screwdriver. How to use a voltage tester screwdriver is three beats: prove the lamp on a known live point, touch the point you care about, then prove the lamp again.

Our top picks

Bosch Professional Bosch SL3x65 phase tester

Best overall

Bosch Professional Bosch SL3x65 phase tester
8.6/10about £5.99
View offer
Rolson Rolson 28110 2-piece pair

Preis-Tipp

Rolson Rolson 28110 2-piece pair
7.9/10about £4.23
View offer
KAIWEETS KAIWEETS contact and non-contact pen

Alternative

KAIWEETS KAIWEETS contact and non-contact pen
6.6/10about £16.98
View offer
On this page
  1. 1.How the neon screwdriver is meant to be held
  2. 2.Prove it, then test, then prove it again
  3. 3.A UK socket, without trusting the diagram
  4. 4.When the lamp lies

How the neon screwdriver is meant to be held

The tip touches the conductor. Your finger touches the metal cap. The path runs through a resistor and the neon, with your body as the return. A training note calls that current small while the resistor is intact, and it does not call the tool harmless once the handle is cracked or wet. Keep it dry, and stop if the plastic is split. A long bare tip can bridge the next terminal, so seat it on one screw. Each driver in a pair has its own lamp, and proving one does not prove the other. The KAIWEETS pen is not this hold: contact mode is a screen, and non-contact mode does not use the cap. The type you bought is in the buying guide.

Prove it, then test, then prove it again

Start on a known live point and look for a glow. If the lamp stays dark, it has not shown you that it works, and you retire it. On a pair, prove the second driver by itself. Do not walk into an unknown terminal and read silence as safety. Then touch the point you care about, one terminal at a time. A glow means you treat it as live. No glow only means this lamp did not strike. Finish back on the known live point. If the lamp does not glow again, the middle beat is void. The three beats do not isolate the circuit.
Bosch Professional Bosch SL3x65 phase tester

Testsieger

Bosch Professional Bosch SL3x65 phase tester
8.6/10about £5.99
View offer

A UK socket, without trusting the diagram

On a correctly wired UK socket, earth at the top, neutral is on the left and live is on the right. That is the BS 1363 layout people expect. You still test the right-hand hole, because a socket can be miswired. Behind a plate, live is usually brown or red. If a socket you believe is live will not light a lamp you have just proved, stop. A socket is not a ceiling rose. The wall switch can be off while the rose is still live. That job is on the voltage tester for changing a light page.

When the lamp lies

Daylight hides the neon. Reviews of these listings call it dim away from a cupboard. Shade the handle and look again. A failed lamp is the dangerous version of the same darkness: the conductor may be live. A wet or cracked handle can bypass the resistor. The lamp can also glow on the wrong wire. DIY FAQ describes a faint glow from capacitive coupling to a nearby live conductor. Treat the area as live, and do not use a faint glow to name a switched live. Stop if the second prove fails, if you need the circuit called dead, or if the job is a consumer unit or paid electrical work. The dead test is a two-pole indicator on neon screwdriver versus a two-pole tester.

Common questions

What do you do before you trust a dark lamp?
Prove the screwdriver on a known live point first. If it does not glow there, the dark reading later is meaningless. After the unknown point, prove it on the known live point again. If you have a pair, each driver needs that sequence on its own. A dark lamp means the neon did not strike, not that the wire is dead.
Why is the neon invisible in daylight?
The lamp is small, and these listings dsaved reviews that call it dim in daylight. Shade the handle and look again. If you still cannot see a glow, you do not have a clear result, and you must not record that as off. A failed lamp looks the same as a dark one. The prove step on a known live point is how you tell those apart.
Can the screwdriver glow on a wire that is not the one you mean?
Yes. A faint glow can come from capacitive coupling to a nearby live conductor, which DIY FAQ notes as a false indication. Treat a glow as live even when you are not sure which wire caused it. Do not use a faint glow to identify a switched live in a rose. If the conductors are ambiguous, stop and use a different instrument.
How do you check both tools in a pair?
Separately. Prove the first driver on a known live point, use it, and prove it again. Then do the same with the second driver. A working lamp in one handle says nothing about the other. One half of a pair can be dead on arrival, and a dead half is easy to read as a dead conductor if you skip its own prove step.
At what point do you stop and use a different instrument?
Stop when you need to prove a circuit dead, when the lamp will not prove on a known live point, when the handle is wet or cracked, or when a glow is too faint to interpret. Paid work and a consumer unit are beyond this screwdriver. HSE GS38 keeps single-pole devices for identifying live equipment. The dead test is a two-pole indicator you have just proved.

Related pages

Prove a circuit dead before you open it

Voltage tester screwdriver

Best voltage tester screwdriver: pick, skip, price

Voltage tester screwdriver: neon, pen, phase tester

Voltage tester for changing a light: UK ceiling rose

Neon screwdriver vs two-pole tester under HSE GS38

Sources

Public UK sources and the amazon.co.uk listings in this comparison. Listings captured 15 October 2026. Page updated October 2026.

  1. HSE GS38: Electrical test equipment for use on low voltage electrical systems (retrieved 15 October 2026)
  2. Electricity at Work Regulations 1989, regulation 12 (retrieved 15 October 2026)
  3. Electricity at Work Regulations 1989, regulation 16 (retrieved 15 October 2026)
  4. HSE HSR25: Memorandum of guidance on the Electricity at Work Regulations 1989 (retrieved 15 October 2026)
  5. NICEIC: Safe isolation procedure in 10 easy steps (retrieved 15 October 2026)
  6. DIN VDE 0680-6:2021-08 phase tester (retrieved 15 October 2026)
  7. DIY FAQ: Neon screwdriver (retrieved 15 October 2026)
  8. Neon tester training note (retrieved 15 October 2026)
  9. amazon.co.uk listings captured 15 October 2026 (retrieved 15 October 2026)