Rinnai continuous flow hot water delivery units and systems can offer unlimited amounts of hot water for hand washing and hygiene in all healthcare operations and associated sites.

Hot water for hand washing and hygiene is a critical component in combating the Covid-19 virus, especially in commercial sites. For many years’ gas fired storage/cylinder tank water heaters where a preferred mode in hot water delivery. However, new technology in the form of continuous flow gives limitless amounts of hot water.

So, now, especially in the times we are in, when a stored water unit comes to the end of its working life or has failed, it is assumed that replacing ‘like for like’ is the best option. If we look back 20 or 30 years, then you could argue that a like for like replacement was the best and easiest solution.

But that was then, and this is now. New technologies and practises are combating the current public health challenge. The technology in hot water delivery is continuous flow hot water heating with constant flows of temperature accurate and controlled delivery.

Any healthcare needing a new hot water heating and delivery method should start with designing and sizing of the system. Before a system is updated it is best to check the appliances that were originally installed are still enough to produce the hot water requirement of the current day.


According to Pete Seddon for Rinnai, the leading UK supplier of continuous flow units: ‘This is something we can offer healthcare operations and essential works right now. It takes this burden away from the site.

‘Now if we look at the ‘like for like’ out with the old one and in with a new gas fired stored water heater – there is actually a major amount of work involved in this.  Changing old for new does not mean it is better. Most plant rooms are limited in space which would require the old equipment removed before the like for like appliances can be installed.

‘Not only that but if the appliance being replaced was non-condensing and the new appliance was condensing then the flue would most likely require changing as well as the provision to discharge condensate. Plant rooms were very rarely designed to remove equipment which could require the old equipment being dismantled before it can be removed. This requirement to remove equipment before new is installed would have a major impact – and it takes so much time. And time is in short supply now,’ adds Pete Seddon.

‘The hot water system would have to be completely shut down to allow such major works to take place and a healthcare site cannot simply allow this to happen.

Due to the size and weight of these appliances it can make life very difficult for installers. They are usually manufactured from Enamel Lined (Glass Lined) Mild Steel which can make it extremely heavy but also very fragile. It would require multiple personnel to manoeuvre these out and in, may be specialist lifting equipment and for plant rooms high up cranes would be required. All of this does not sound easy which will add a lot of time and cost to the overall installation. Not only that but if specialist lift equipment and cranes are required you are going to need suitably trained personnel as well as permits.

‘So, what can continuous flow solutions offer that can make this whole process a lot easier? Well, we will start with their size and weight. This type of technology is normally a similar size to a modern-day combi boiler but only weighing at most 30kg. That is a one-man lift. In this box packs a punch as well with two sizes available in 47kW and 58kW. This would equate to a large volume of hot water for such a physically small appliance. (774 and 954 litres per hour at a 50-degree rise)

‘The other benefit is the ability to cascade these appliances so when more hot water is required you would simply add more continuous flow water heaters. This would mean that just a single installer could create a system that would produce vast amounts of temperature accurate hot water. Whilst also creating built-in redundancy – what is meant by this is that if one unit needs to be shut down the whole site still has ready access to hot water.

Also possible is a ‘plug and play’ cascade sequencing control system that will automatically control how many appliances are running at any one time, all the installer would have to do is plug it in and select the primary water heater. Continuous flow can easily cope with any size of healthcare site. Simple as that,’ added Seddon.

‘These appliances are generally considered wall mounted but by utilising a cascade frame this removes the requirement of wall space. The cascade frame is generally lightweight, and two engineers can easily carry into a plant room. No material handling nightmare.


‘One of the big benefits we have seen with the utilisation of the cascade frames is the fact that a lot of the installation works can be carried out while the existing equipment is still in place. This would obviously depend on floor space within the plant rooms, but we have seen first-hand that this tends not to be an issue. The cascade frames would be bolted to the floor and the water heaters mounted on to the frames. This will then allow some of the pipe work to be started as well as some of the flueing installation. All that is left to do would be to connect the pipework to the existing system finish off the flue and then the system is ready for testing, purging, flushing etc. This would even be the case if the water heaters were wall mounted.

With a continuous flow system there are also externally sited units where is just no space in a plant room. These external hot water heaters are fully weather protected with and hold IPX5D rating. They also come with frost protection down to -20°C and will keep the appliance protected so long as the mains power supply is left switched on.

During the lockdown Rinnai continue to offer full support services to essential works such as all NHS facilities, care homes, schools and supermarkets etc This operational support to Essential works during the lockdown has had such a huge response that the company has committed to maintaining and continuing for the duration of it – and beyond.

Provided there is a constant supply of gas and water the Rinnai units are guaranteed to supply temperature accurate hot water in unlimited quantities for all hygiene regimes in all types of healthcare sites or temporary accommodation.


• Rinnai services to essential works and installers are: –

Rinnai’s Runcorn UK HQ emergency weekend opening and sales support – open for any emergency/essential equipment provision of new units and for spares.


• Weekend operational and technical support help line – simply call 01928 531870 and select sales and if the call is not answered immediately leave a voicemail and the company will respond within an hour.


• Collection of new units/spares from Runcorn HQ for Saturday and Sunday. All will adopt ‘safe distancing’ in any contact for this or deliveries.


• Emergency delivery on working days and weekends / out of hours – under “essential works” circumstances and, where possible, Rinnai will readily offer a delivery service to site.


Out of hours and weekend technical support – installers, site managers, contractors and all end-users simply call 01928 531870 select technical and if the call is not answered immediately leave a voicemail. Response will be within one hour between 0800 – 22:30/7 days a week. This means that there be a technical response every day of the week.


Rinnai’s complete range of hot water heating units is available for next day delivery on orders placed before the previous mid-day. Rinnai UK has excellent stock levels of all units in the range plus spares and accessories.

Installers can contact the company direct in gaining access to the supply of units –

Call T: 01928 531 870 or E: and or alternatively use the smart online contact points “Help Me Choose”  or “Ask Us a Question”, all held on the website homepage at