Service please!

25th Oct 2016


When selecting an unvented hot water cylinder, factors like performance, build quality and efficiency are all high on the list. However, an annual service is vital to ensure the chosen and installed product can perform as intended.

In recent years there has been a significant shift in demand for hot water cylinders, as trends for hot water requirements have changed in line with modern lifestyles. In fact, 80 per cent of house buyers have been found to consider the number of bathrooms to be a significant factor in choosing a home. Furthermore, a typical buyer looks for at least two bathrooms for every 3 bedrooms, with just over a third considering it essential to have an en-suite for every bedroom.

All this spells growth for the unvented hot water cylinder market, as hot water cylinders are able to meet high levels of hot water demand. By installing an unvented hot water cylinder, a homeowner can look forward to high pressure showers and fast filling baths – but despite being a significant cost to buy and install, many consumers remain unaware of the regular maintenance required to protect their investment.

Richard Newman, commercial product manager at Heatrae Sadia, HWA member, explains the importance of regular servicing.

“While a high proportion of homeowners would recognise the need to have their boiler serviced annually, very few know that to keep their hot water cylinder running properly and efficiently, simple maintenance procedures need to be performed.

Awareness will be higher amongst installers; however without communicating that knowledge to the homeowner the maintenance involved will most likely be overlooked.

When installing a hot water cylinder, installers should take the time at handover to talk to consumers about the need for annual servicing. By explaining what can happen to a system over time through everyday wear and tear, consumers will be more likely to appreciate its relevance and act accordingly. What’s more, by raising the issue, installers can position themselves as trusted advisors, building a longer-lasting relationship and most likely securing the regular job of servicing later down the line.

 One of the first points to mention is that of hard water, which affects over 60 per cent of England – particularly the South, East and middle of the UK. Over time, hard water can result in limescale deposits on immersion heaters, similar to those that consumers would see on their kettle – affecting its ability to operate effectively. Annual servicing provides a useful route to monitoring affected parts and replacing them if required, which is much more cost effective than having to replace the full cylinder because the damage is too great. It’s worth noting that a scale reducer is recommended in areas where limescale exceeds 200 parts per million (ppm). 

Equally important is the safety checks which form the cornerstone of any annual service. Homeowners may not realise that unvented cylinders store water in a sealed vessel under high pressure and at high temperatures. In commissioning an annual service, they can be certain that the safety valves will function properly in the event of a fault.

Another point to mention is the performance of the system. The annual service provides an opportunity for the householder to report any concerns that have come to light, particularly with reference to water pressure. Installers can check that the tank is working to maximum efficiency, reducing the risk of breakdown and keeping energy consumption to a minimum.

Finally, homeowners should be aware that in most cases, failure to have the hot water cylinder serviced annually can invalidate the product warranty, meaning higher costs in the long-term when it comes to call outs and replacement parts.”

Installers should be aware that to fit or service an unvented hot water storage system, they should complete a recognised course for the installation of unvented hot water systems to become a ‘competent person’ in line with Part G3 of the Building Regulations. Training is offered by a number of providers such as the CITB, BPEC, APHC, Zurich Certification and SNIPEF, as well as some colleges and manufacturers. The Hot Water Association, HWA, recommends that any maintenance or service of the tank should be accompanied by the completion of a Benchmark Installation, Commissioning and Service Record.

Regular servicing is an important route to maintaining a domestic hot water system, helping to ensure predicted energy efficiency, performance and longevity, as well as peace of mind for the homeowner – and yet often it is overlooked. Installers can play a key role in raising awareness of the need for servicing, supporting their customers in enjoying trouble-free service from their water heater and delivering improved customer satisfaction as a result.


As ever, HWA members will be pleased to offer advice on best practice. Member details can be found at