NOT USED Hot Water Risks and Hazards

Next

• Scalding and burning​
• Carbon monoxide poisoning ​
• Explosion ​
• Corrosion and water damage​
• Legionella disease ​
• Unsafe electricity

The risks associated with domestic water systems include the following:​

Risks, hazards and how to mitigate them

Next

Safety

Ensuring hot water safety is vital in residential properties, to safeguard the occupants and preserve the integrity of the building and its structure. Hot water can present a substantial health hazard if not installed correctly and subject to regular inspection and maintenance.

Info

Info

Info

Info

Risks to people

All modern hot water systems are connected to electrical controls.

Legionella is a bacteria that grows in water between 20-45 °C.

Carbon monoxide (CO) is a silent killer; it is odourless and colourless.

Most commonly occurs in baths and showers.

Electrics

Legionella

Carbon monoxide

Burns and scalds

Next

Info

Info

Risks to buildings

An explosion is the most extreme risk with domestic hot water systems.

Leaks are the most common and obvious risk to a building.

Explosion

Leaks

Next

Link

Back

See some of the issues leaks can cause by selecting the icons on the images.

• In both situations repairs should be undertaken immediately to avoid it worsening.

• It may involve landlord or home insurance to cover these sorts of risks.

Risks to the building and fabric

LOREM IPSUM DOLOR SIT

Link

If a cylinder explosion fractures or rips out the gas pipe, this can result in a fire.

Back

Explosions pose the greatest danger to both occupants and buildings. Safety features like vents and relief valves help manage overheating by releasing water although issues often stem from shoddy work or neglecting maintenance. It takes time for water to boil and change state. Under pressure, water remains liquid at higher temperatures. If this pressure is released, it results in rapid expansion or an explosion - a large volume of water heated above 100 °C, remaining a liquid as it can't escape. Eventually, the pressure will be too great causing a mass amount of water to vaporise into a gas. Read about a cylinder explosion:

Risk of explosion

• Cylinder explodes
• Boiler leaks acids
• Boiler leaks pressurised boiling water

Reveal

• Hydrogen chloride
• Nitrogen
• Carbon monoxide

• 10°C - 20°C
• 20°C- 45°C
• 40°C - 55°C

Reveal

Reveal

2. The risk of Legionella increases when water is stored at what temperature?

3. What is the most extreme risk a hot water system can pose to a building?

Next

1. What is the odourless and colourless, poisonous gas produced by incomplete burning of carbon based fuels?

Try a few questions

Reveal

Reveal

Reveal

it is a gravity system

If the cylinder is in an airing cupboard and storage tanks in the loft...

it is a pressurised unvented system

If the cylinder has an expansion vessel and pressure relief valves...

Next

it is a sealed system​

If it has a combination boiler ...

Identify the system type!​

Visually checking a system can provide valuable information about its condition, such as the age and maintenance level of taps, pipework, and appliances. It is also important to refer to technical information or manufacturer instructions to ensure proper installation and service history, including details about the installer and each service performed on the system.

Know what you're looking at first!

Reveal

Reveal

Reveal

it is a gravity system

If the cylinder is in an airing cupboard and storage tanks in the loft...

it is a pressurised unvented system

If the cylinder has an expansion vessel and pressure relief valves...

Next

it is a sealed system​

If it has a combination boiler ...

Identify the system type!​

Visually checking a system can provide valuable information about its condition, such as the age and maintenance level of taps, pipework, and appliances. It is also important to refer to technical information or manufacturer instructions to ensure proper installation and service history, including details about the installer and each service performed on the system.

Know what you're looking at first!

Reveal

Reveal

Reveal

Reveal

Gate Valve - Low Pressure Isolation

Lever Isolation Valve

Water Isolation valve

Gas Isolation Valve

Now you know the system's age, type, and history, you can check for defects that might lead to unsafe situations. Key things to check on each system will slightly differ, but it will help to identify possible DIY works, age-related issues, or poor workmanship. Do you recognise these valve types?

Next

Correct valve for the correct job!

If in doubt, talk to a professional!!​

Tradespeople must be occupationally qualified and registered with a competent person scheme to work on hot water systems. If you suspect something is incorrect or unsafe, or you are unsure, seek advice from an approved, qualified plumber.

Next

Check the area for signs of leaks. Wet or damp patches could indicate this.​ Check for signs of scaling on the whole system, this can result in a diminishing of efficiency and a risk of blockages. ​ Listen, run the hot taps and if you hear loud banging or vibrating, the system might not be clipped or supported properly.

Things to check​

Next

Hover over the images to reveal the information

Health and Safety considerations​

Select the images to access the resources

Common Visual Faults Table

Boiler Guide: Common Hot Water Cylinder Problems

British Gas: What to do if you have no hot water?

EDF Energy: 10 common boiler problems

Common Visual Faults

Legionella causes Legionnaires' disease, which can be a serious illness. To prevent this:

• Systems should be designed and maintained to ensure small runs of pipework.
• Ensure hot water is adequately heated above 45 °C to kill the bacteria and prevent it from growing.

Link

Electrical controls like pumps, immersion heaters, and zone valves depend on electricity to function efficiently. Incorrect installation, such as wrong cables or placing controls in unsuitable areas, can pose electrocution risks. Regular maintenance by professionals such as plumbers, electricians, and gas engineers is essential for safety. It helps prevent issues like poor workmanship, outdated controls, inadequate safety features, and ensures proper electrical earthing. Read more about electrical safety with the HSE:

Link

Link

Burns or scalds happen when hot water comes into contact with the skin, often during activities like bathing or showering. Regulations exist to prevent such accidents, which we'll explore in the following sections. The HSE provides guidance on why water is heated to high temperatures and how to reduce the associated risks.

Link

Carbon monoxide (CO) poisoning stems from incomplete combustion in heat-producing appliances like boilers, commonly used for heating water in homes. It can occur in both modern pressurised systems and older gravity systems. CO is dangerous because it's odourless and colourless, posing a silent threat that can lead to severe illness or death. Proper installation and regular maintenance of heating systems are crucial in preventing CO poisoning. Installing CO detectors and ensuring adequate ventilation further minimizes the risk.

Legionella causes Legionnaires' disease. This can result in severe illness. To prevent this:

• Systems should be designed and maintained to ensure short runs of pipework and to
• Ensure that hot water is adequately heated above 45 °C to eliminate the bacteria and prevent its growth.