Is it acceptable to test just a sample of my fixed electrical system and not the whole thing?

Some electrical contractors will quote to test your system based on testing only a given percentage – typically 10% to 30%. This means they offer a lower cost, which can seem attractive.

However, industry best practise advises against this.

One reason is that Guidance Note 3 (Inspection & Testing) of the 17th Edition IEE Wiring Regulations BS 7671: 2008 recommends that the results of tests should be compared with those taken when the installation was last tested and any differences noted.

If a significant difference is noted, then a full investigation should be undertaken because this is a potential indicator of a fault in the system.

If you are only testing a small, different portion of the system each time then you will have no previous results to compare against and may miss a fault.

And if you only test the same small area each time then the rest of the entire system will be going untested and faults will go unnoticed until an accident happens. Unfortunately, if an accident does happen and you can not produce proof that you did all within your power to ensure the safety of the entire system then you and your organisation may be liable for prosecution.

In addition, many insurers will require a full system EICR as part of their contract with you.

As such we strongly recommend that full electrical system testing and maintenance is undertaken.