If you are a landlord and you are renting out for property then by definition that would make you a commercial entity, which by extension means you MUST comply with Electricity at Work Regulations.
Attached should be 2 publications from the HSE,
HSR25 - Memorandum on The Electricity at Work Regulations
HSG85 - EAWR Safe Working Practices.
(If they haven't attached, just Google 'HSG85' and 'HSR25', or just EAWR)
HSR25 explains every regulation in detail and how to comply. As a landlord the one you want to pay particular interest to is Regulation 29
Defence. 29. In any proceedings for an offence consisting of a contravention of regulations 4(4), 5, 8, 9, 10, 11, 12, 13, 14, 15, 16 or 25, it shall be a defence for any person to prove that he took all reasonable steps and exercised all due diligence to avoid the commission of that offence.
In short; Did you do everything you could to prevent danger or matters that may give rise to danger.
There are others in there that govern,among other things
- Safe working practices
- Connections
- Protection
- Competency
The latter is the most important as a person that is competent should be able to comply with the other regulations with relative ease.
Read the aforementioned documents, any questions by all means come back with them.