Legionnaires' disease is a potentially fatal form of pneumonia that particularly affects people already more at risk due to age, illness or who suffer with a low immune system. It can also cause less serious illnesses. The bacterium Legionella Pneumophila, which is often present in natural sources of water, can multiply to harmful levels in manmade water systems so it's important to assess the risk of Legionnaires' before letting property.
The law is clear that if you are a landlord and rent out your property (or even a room within your own home) then you have legal responsibilities to ensure the health and safety of your tenant by keeping the property safe and free from health hazards.
Health and safety law does NOT require landlords to obtain, produce nor does HSE recognise a ‘Legionella test certificate’. However, landlords must undertake a risk assessment of the water system to ensure the tenants are not exposed to Legionella.
Carrying out a risk assessment is your responsibility. You may be competent to carry out the assessment yourself but, if not, you should call on help and advice from either within your own organisation or from outside sources, e.g. consultancies.
It's important to remind your landlord clients of their legal obligations and signpost to advice and or services. If you fully manage the property, then as the managing agent you are responsible for providing a safe water system.
If you do offer a risk assessment service but your landlords client declines this, then it may also be wise to get written confirmation that they intend to deal with the issue themselves.
HSE and Local Authority inspectors do not proactively inspect domestic premises, or ask for evidence that landlords have undertaken a risk assessment. However, if a tenant were to contract Legionnaires’ disease from the water system in their home, the landlord may be liable to prosecution under Health & Safety at Work Act and would have to demonstrate to a court that they had fulfilled their legal duty, so it is important that they assess and control the risks.
More information can be found here: http://www.hse.gov.uk/legionnaires/faqs.htm