Getting out of hot water

Published:  05 July, 2012

B&ES, DHW, legionella, TMV, scald
Sensible attitudes to hot water — Blane Judd.

The current programme of modernising hot-water systems to improve energy efficiency is also the perfect opportunity to tackle the ongoing threat of scalding, says Blane Judd of the Building & Engineering Services Association.

It took many years of dogged campaigning, led by the Royal Society for the Prevention of Accidents (RoSPA), to get a crucial amendment to Part G of the Building Regulations. This means that all new-build homes across England and Wales must now have devices fitted to baths and sinks to limit the temperature of their water to 48°C.

Campaigners were jubilant — despite a further one-year delay caused by the European Commission’s concerns that the change might constitute a barrier to trade. Eventually, the provision came into effect in October 2010. Yet, this battle is far from won.

The new measure is not retrospective, which means the threat of scalding remains very real in existing buildings. Regulators weighed the potential benefits against the huge cost of retrofitting thermostatic mixing valves (TMVs) or other devices and felt that the programme would simply be too large and expensive.

The simplest and cheapest solution, for many, has been to put up signs warning people that the water they are about to use is very hot. Large commercial toilets in motorway service areas sports stadia and so on often display signs that water is very hot — but it is a moot point whether this meets any legal obligation. What are the implications for blind people, for example?

Concerns about the build up of legionella bacteria have led to many hot-water systems being programmed to store water above 60°C. Higher temperatures also mean it is possible to use smaller storage cylinders to cut water wastage and reduce energy consumption.

However, this practice means that most water in our buildings is kept at a temperature that can cause scalding. Anything above 45°C can lead to injury and once you are above 60°C it is possible for serious harm to be caused in just a few seconds. Using TMVs allows engineers to design systems that store water at relatively high temperatures, but dispense it safely.

The Workplace (Health, Safety & Welfare) Regulations 1992 do not make specific recommendations about the temperature of water used in commercial washing facilities. However, codes of practice recommend that showers for workers and members of the public should be fitted with a device, such as a TMV, to prevent users being scalded.

The Health & Safety Executive (HSE) has published guidance on water temperatures in care homes to protect vulnerable residents. When water temperatures are in excess of 44°C, there is a high risk of burns or scalds to the elderly and children. ‘Anyone with reduced sensitivity to temperature or anyone who cannot react appropriately, or quickly enough to prevent injury will be at risk,’ it says.

RoSPA believes that around 500 children are admitted to hospital every year in the UK because of scalding and that a further 2000 are taken to accident and emergency units.

This is not just about taps. There have been a number of well publicised incidents in the past few years where hot water from hot-water cylinders heated by immersion heaters has been vented into cold loft tanks, which eventually burst — pouring scalding water down into bedrooms. A number of babies and young children have died from this type of product failure.

Although all new immersion heaters now have overheat protection built in, there are still around 3.5 million homes in the UK thought to have old-style units. This emphasises the importance of ongoing service and maintenance in reducing risk, particularly in systems that are more than 10 years old.

Homeowners and landlords should be particularly wary of systems that comprise all-electric or part-electric immersion heaters used in conjunction with a plastic cold-water storage cistern or tank in the roof space. In at least two of the fatal cases, it was revealed that serious installation mistakes had been made.

The cold water tanks had not been supported properly and, if they had, they would have lasted long enough to alert occupants to the problem before the tanks collapsed.

Other countries have had regulations governing TMVs and immersion heaters for some years, and their experience shows that serious injuries can be reduced by as much as 50% by widely deploying anti-scald technology. The Building & Engineering Services Association (B&ES), along with other industry bodies, is pushing for similar legislation in the UK calling for maintenance of hot-water systems to ensure they are retrospectively fitted with TMVs or other methods of controlling the temperature of the water that emerges from our taps.

Simply tackling the problem through the measures in the revised Part G that only apply to new homes will take decades. Our industry is right in the thick of efforts to improve existing buildings, and that is where we must also focus on this issue.

TMVs are an excellent innovation and should be fitted wherever possible. With the industry embarking on the biggest renovation of buildings since the Second World War to improve energy efficiency, we also have a great opportunity to tackle the scalding problem at the same time.

Many hot-water systems are being upgraded to meet new energy-efficiency standards, and we are also seeing the widespread adoption of solar-thermal systems to reduce carbon emissions. Heating water is the single most energy intensive activity in a modern home. With Green Deal funding available from this October, we have a great opportunity to modernise thousands of systems by adding TMVs and removing old, unsafe appliances at the same time.

Ongoing service and maintenance then has to be put in place to make sure our efforts are not wasted and systems are regularly checked for safety and efficiency.

Putting up a sign might be the easiest way of warning someone that the water they are about to use is hot, but surely it makes more sense to have the water delivered at a sensible temperature in the first place.

Blane Judd is chief executive of the Building & Engineering Services Association (B&ES).



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