Identify the type of hot water system installed in the property.

Typical domestic systems include:

• combination (combi) boiler
• boiler with hot water cylinder
• electric water heater or immersion heater

Where a hot water cylinder or electric storage heater is present, the thermostat should normally be set to approximately 60°C.

This helps prevent the growth of Legionella bacteria in stored hot water.

Carry out a general walk-through inspection, similar to a normal annual property inspection.

Look at visible plumbing and pipework and check for:

• dead legs in pipework
• redundant pipe runs
• dog-legs in pipework
• capped pipes where radiators or appliances have been removed

These areas may allow water to remain stagnant.

If pipework has been capped off after removing a radiator or appliance, the pipe should ideally be removed back to the main circulating pipework.

Using a digital thermometer, run both hot and cold taps for approximately 1–2 minutes.

Record the temperatures.

Typical guidance temperatures are:

Hot water should reach approximately 50°C or above at the tap.

Cold water should ideally remain below 20°C.

Maintaining appropriate temperatures reduces conditions where Legionella bacteria may grow.

If the property has a combination boiler, check that the hot water temperature setting is appropriate.

If the property has a hot water cylinder or electric storage heater:

• check the thermostat is set to approximately 60°C
• this may also be confirmed by measuring the temperature of the hot outlet pipe leaving the top of the cylinder

Instant electric heaters generally store little or no water and are therefore normally considered lower risk, although outlets should still be kept clean and used regularly.

Determine whether the cold water supply is:

• mains fed, or
• supplied by a cold water storage tank

If a cold water storage tank is present and it is safe to access, check that:

• the tank has a secure lid
• the tank appears clean and free from debris
• the tank and pipework are adequately insulated

Cold water tanks are often located in loft spaces.

If safe access is available (for example with a loft ladder and suitable boarding), the tank may be visually inspected.

If the loft cannot be safely accessed, inspection should be limited to what can be viewed safely from the hatch.

If the hatch itself cannot be accessed safely, this should be recorded in the assessment.

Check whether the property has any showers installed.

Inspect:

• shower heads
• shower hoses
• tap outlets

These should be clean and free from heavy scale or debris.

Showers are one of the main areas where water droplets may be inhaled, so keeping them clean is good practice.

Look for outlets that may be rarely used, such as:

• spare bathrooms
• guest en-suites
• utility sinks
• outside taps

Where outlets are not used regularly, it should be recommended that they are flushed through if unused for more than two weeks.

Regular use helps prevent water stagnation within pipework.

In most domestic properties where water is used regularly, the Legionella risk will normally be considered LOW.

This assumes that:

• water systems are used regularly
• temperatures are within normal ranges
• there are no obvious dead legs or redundant pipework
• outlets are kept clean

Any issues identified during the inspection should be recorded together with recommended actions.

Landlords have a duty to ensure that their property does not present a risk to the health and safety of tenant's or visitors.

Guidance from the Health and Safety Executive (HSE) states that landlords should assess and control the risk of exposure to Legionella bacteria in domestic water systems.

A Legionella risk assessment does not normally need to be completed by a specialist, provided the person carrying out the assessment is competent and understands the risks and control measures.

Reading and understanding the guidance within this document should provide sufficient knowledge to carry out a basic domestic Legionella risk assessment.

However, the legal responsibility for managing Legionella risk always remains with the landlord.

This assessment reflects the condition of the water system at the time of inspection and is based on a visual inspection of accessible areas only.

Maintaining a low level of risk relies on the continued normal use and maintenance of the water system, including regular use of outlets and following any recommendations identified in the report.

Extended periods where the property is unoccupied or outlets are not used regularly may increase the risk of stagnation, and outlets should be flushed when the property is reoccupied.