Range from the cheapest fixing an electrical fault £88 (Hemiko based in SE1) to the dearest fixing of an electrical fault £96 (S P L Construct Ltd based in EC4N).
Comparing electricians estimates for troubleshooting and diagnosing an electric fault gives you an idea of who will be better value but the best way to compare costs is to get actual quotes.
What to do - Get rates and quotes to fix an electrical fault in EC3M by posting a job with HaMuch and we will send it to electricians in EC3M.

"Troubleshoot & diagnose electrical fault"
E1