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12 volts on some plug and light switch screws.


I recently replaced a blanking plate as the old screwless one was falling off.

Using a direct test voltage pen from homebase I noticed the screws on some plug sockets and light switches show 12V.

What could cause such a low voltage? It appears to only be upstairs, the house was built in 1996 and the previous owners have done some minor electrical work.

More importantly, is this safe? The house does have an up to date electrical certificate stating it is satisfactory.

Thanks for any advise you can offer!

2 Answers from MyBuilder Electricians

Best Answer

Those detector pen things should be done away with imo. I suggest you get an EICR done on your property. These pens are liable to give false readings whereas if you get an EICR done all the testing will be done by a calibrated tester. It will also cover the minor work covered by previous owners. It will either pass or fail.


Answered 13th Mar 2017

The 'Volt stick pens' are , at best, ok for detecting a voltage. And that is just where it ends. A qualified electrician would not rely upon one for ANY testing. Appropriate , certified testing kit is the only answer. To the may have a voltage leak from various items, or a poor earth on double insulated items such as pc, high-for, DVD player, or even a neon.But you will NOT find it with a Voltstick !!


Answered 13th Mar 2017

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