Domestic hot water temperature UK

Domestic hot water temperature UK – a picture showing hot water flowing out of a tap

According to the HSE, domestic hot water must be kept in the cylinder at a minimum of 60 degrees Celsius to destroy legionella bacteria , which unfortunately can be fatal for human beings.

Therefore, the best temperature or ideal temperature for your hot water tank is 60 °C, as 90% of the bacteria will die in only two minutes if the hot water tank temperature is 60 °C. If the temperature of the hot water tank is raised to 70 degrees Celsius, all of the Legionella bacteria will die right away.

Hot water tank temperature for your hot water cylinder

In the UK, the hot water tank’s temperature should range from 60 °C to 65 °C.

There is a higher chance of bacteria like Legionella, which causes Legionnaires’ disease, developing if the temperature is below 50°C. When your water has been sitting in the stored hot water tank for some time, this occurs.

The water will be too hot to use and the danger of severe burns will rise if the temperature rises over 65°C. The water is hot enough to use and hot enough to destroy harmful bacteria when kept at a safe temperature of 60 °C to 65 °C.

Hot water cylinders or tank

Hot water tanks must now be equipped with a thermostat that allows the user to control the temperature of the water within. You can monitor the hot water tank temperature of the tank on your phone these days using a hot water temperature sensor installed in the hot water cylinder.

unvented hot water cylinders indirect

Cut away picture of our indirect cylinder Flexiheat UK

Our indirect unvented cylinders or direct unvented cylinders that we supply both have a thermostat to control the hot water temperature to your requirements.

Legionella, what is it ?

The word “legionellosis” refers to a group of illnesses brought on by the legionella bacteria, including the most severe one, Legionnaires’ disease, as well as the comparable but less dangerous Pontiac fever and Lochgoilhead fever. The potentially lethal pneumonia known as Legionnaires’ disease can infect anyone. Age-related risk is higher for certain people than for others, such as:

  1. Any person whose immune system is compromised

  2. Those with chronic kidney or respiratory diseases.

  3. People suffering from cardiovascular, pulmonary, and diabetes diseases.

  4. Those who smoke and drink heavily.

  5. Individuals who are over 45 years of age

In natural water sources, including rivers, lakes, and reservoirs, the bacterium Legionella pneumophila and related bacteria are widespread but often in low concentrations. They may also be found in specially designed water systems, including spa pools, evaporative condensers, cooling towers, and hot and cold water systems.

In order to reduce the dangers of legionnaires’ illness, it is crucial to eliminate favourable circumstances for legionella risk.

How does one get legionnaires ?

People get Legionnaires’ disease by breathing in aerosolized water droplets (aerosols) that are suspended in the air and carry the bacteria. The following circumstances raise the risk of legionella:

Legionnaires disease caused by low stored hot water temperatures in hot water cylinders in the UK

 

The hot water temperature in the system may range from 20 to 45 °C in the hot water cylinder or domestic hot water system, which is ideal for development.

It is possible to produce and disperse breathable water droplets, such as aerosol, from a cooling tower or hot water outlets, such as sink taps, bath taps, or showers.

When water is stored and/or recirculated, deposits like rust, sludge, scale, organic waste, and biofilms can help bacteria grow and feed the organism.

Thus, it is vital to reduce the risks to the health of individuals, be they staff or customers on your business site, or home owners or occupants.

The majority of people who become ill and require hospital treatment ultimately survive and recover completely.

However, roughly one in ten individuals who contract Legionnaires’ disease passes away from the illness.

What temperature should domestic hot water be in the UK

We’ve established that is hot water tank temperature should be 60 C to 65 degrees Celsius which means that any gas boilers or oil boilers should be supplying the indirect cylinder with a hot water temperature above that figure to ensure the cold water coming into the hot water cylinder gets heated up to the right temperature.

Alternative methods of heating the hot water tank, such as a solar water heating system or heat pumps, are also becoming more common these days as we look to reduce and save carbon emissions from gas boilers or oil boiler heating system.

There are some issues with regards to using heat pumps instead of a heating boiler, as they can struggle to heat the water system, as at present the maximum heating temperatures of a heat pump are around 55 °C, which means they don’t generate the right temperatures required for domestic hot water heating.

This is remedied by using an immersion heater to raise the tank water temperature from 55 degrees Celsius to the required 60 degrees Celsius.
The immersion heater or heaters, depending on the hot water tank size, are normally electrically supplied with power.

Combi boilers, on the other hand, produce hot water on demand and have no stored hot water tank. Thus, these types of gas or oil boilers can supply the hot water system at lower hot water temperatures , which also helps save carbon emissions, energy and money for your economical domestic hot water heating system.

The hot water tank accounts for 14% to 18% of the energy consumed by the typical household.

Domestic hot water systems in the UK

There are two main systems for heating hot water used in the United Kingdom.

Stored domestic hot water

normally produced via a boiler in conjunction with an indirect cylinder. The thermostat on the hot water tank controls the boiler, which you simply adjust to your requirements.

On demand or instant hot water:

An on-demand water hot system normally saves energy and money ( normally around 30% less energy when compared to hot water storage systems ) as they efficiently allow the bath, shower, and tap water supply to be at a lower temperature—around 40C to 43C while washing. This warm water temperature eliminates the risk of scalding when having a shower, bath, or using a hot tap as this heated water is under the supply temperature of 44°C at which scalding risk to vulnerable people can occur.

Instant water can be provided by a gas water heater , which we have a full range detailed on this dedicated webpage: gas water heaters , which are available in natural gas or LPG (Propane) gas.

gas water heaters energy efficient hot water heating from Flexiheat UK

Gas Water Heaters

In many households in the UK , a combi boiler or combination boiler is the most commonly used appliance as they do both the heating and water system. The boiler has a thermostat, which allows temperature control of the DHW water.

This thermostat dictates the water temperature to the supply pipe running to your warm water outlets, such as your hot water tap, shower, or bath tap.

As the boiler doesn’t have to heat the water up to 60 °C like a stored warm water tank, they benefit from lower energy requirements and eliminate scalding potential .

Our combi or combination boilers are detailed on this webpage: LPG combi boilers. We also do these units in natural gas too.

combination boiler from Flexiheat UK

Combi boiler  from Flexiheat UK

 

Conclusion

The hot water temperature for your hot water tank will be different to the hot water temperature used on an instant water heater , as the stored warm water must be 60C or over, and when producing it on demand , it can be lower, circa 40-43C, depending on your requirements to save energy.

Industrial water heaters Gas or Electric

Industrial water heaters Gas or Electric

Industrial hot water heater or hot water heating via indirect water heaters or an on-demand water heater - Flexiheat UK

An industrial water heater provides a domestic hot water system – also know as DHW – which delivers hot water to fixtures used by people at the sink, in the shower, or bath and any other location where warm water may come into contact with humans for bathing or washing up etc. Hot or warm water may also be required for food and beverage commercial and industrial applications, processing or wash down industrial applications in abattoirs etc.

Commercial and industrial applications

Hot water systems or water heaters for commercial or industrial applications can cover hot water requirements for-

Commercial applications – commercial water heaters

Locations such as hospitals, hotels, swimming pools, schools, camping facilities, or sports or leisure centres may be considered commercial hot water heating applications, and thus require commercial water heaters, but we would consider a hospital, due to the way they operate and the capacities of domestic hot water they require, which can run into thousands of litres of warm water per hour.

On demand water heater or water heating for health care environments Flexiheat UK

Hot water systems for hospitals or health care environments

 

But there is no hard and fast rule when it comes to commercial water heaters, and when a commercial water heater becomes an industrial water heater as such.

A picture of indirect water heaters in a hospital hot water heating system Flexiheat UK

Indirect Water heaters – for a hospital or a food or beverage processing plant water heating requirements

 

Most people go with the gas safe qualifications, in that for any gas appliance over 70kW input, the heating installer must have an industrial gas certificate or qualification to do the installation, so this seems like a good defining point when it comes to the difference between commercial water heaters and industrial water heaters.

Industrial hot water heaters

Industrial hot water systems or hot water heaters tend to be installed, developed and designed for process hot water applications such as food production, preparation, or wash down services, which can require high levels of hot water supply with regard to litres and often at high water heating temperatures.

high pressure hot water heating systems or products for food and beverage production with Andrews water heaters services

Solutions for warm water requirements for food and beverage production by Flexiheat UK

These factors make our gas water heaters our most popular product range when it comes to solutions for water heating systems. Because gas delivers a remarkable amount of energy through a relatively small pipe, and because of recent legislative changes, any industrial gas water heater must now be condensing to provide maximum efficiency and benefits in reducing greenhouse emissions.

A water heater for a process application is normally just a simple calculation of the volume of water required and the temperature rise required.

Heat pump hot water heating

Heat pumps aren’t suitable water heating solutions at present as they can’t achieve the required water temperatures that the customer often requires, as heat pump systems can only achieve a temperature in the 50 to 55C range. To get up to the required stored water temperature of at least 60 °C, they have to use electric immersion heaters to top up the heat supplies—in essence, they can be called hybrid water heaters.

Whether the technology for heat pumps develops so they can achieve the higher hot water temperatures and kW capacities is to be seen. Hopefully so, as they have high efficiency. If you have the power supply available, as these units normally require a 3 phase electrical connection and take up a lot of space as storage tanks are normally required as accessories.

At present, heat pumps products aren’t really suitable for domestic water heating systems for commercial and industrial applications.

Electric water heaters

We have a dedicated electric water heaters web page that goes into full detail on the capacities in litres of the tanks and kW ratings available here.- Electric industrial and commercial water heaters

commercial electric water heaters; commercial electric hot water heater; industrial electric water heater; industrial electric hot water heater;

Commercial & Industrial electric water heaters from Flexiheat UK

 

We also supply an instantaneous three phase heater range, detailed here – three phase water heater range

Industrial gas water heaters

As mentioned previously, our gas water heater range is the most popular hot water systems for industrialised requirements due to the high pressure, kW, and heat output the range can produce.

The cost-to-output makes this water heater range a favourite with many a trading customer of ours.

We do a range of gas instantaneous water heaters with an output up to 400 kW which can provide up to 174 litres / minute of domestic hot water, with a high modulation ratio of 1 to 60.

instantaneous gas water heaters; gas water heaters in cascade; lpg multipoint water heater; gas fired condensing water heaters; condensing water heater;

instantaneous gas water heaters- condensing in cascade complete with pipework rig from Flexiheat UK

Full details are listed on our dedicated gas water heaters webpage here – industrial gas hot water heating

Or if you require large gas fired instant hot water production then these are detailed on this webpage commercial instantaneous water heater options

Or we can use these units with a DHW storage tank to account for peak demands or loads which are often found in process applications – these are detailed here – Domestic hot water storage tanks 

Contact us

Should you require any more support, selection and design expertise or cost on our industrial water heating products for commercial and industrial applications with high capacities in terms of litres and kW output, then please fill out your details on the contact us form page on the website, or feel free to contact our UK sales team professionals on 01202 822221 who are on hand to support and assist you with any part of your hot water heater project. Follow us on Facebook or Twitter for an overview of our latest news and products.

Main multipoint bf water heater new replacement

Main multipoint bf water heater which is a gas fired instantaneous hot water heater

If you are looking for a main multipoint BF water heater, then the bad news is that these gas fired water heaters are no longer available, whether it was the standard model, which was obsolete in 2018, or the ERP model, which was discontinued in 2019.

This gas-fired instantaneous water heater brand and model was an advanced balanced flue 24 hour a day space-saving on-demand water heating unit with no storage tank and a copper heat exchanger.They were a hot favourite for hot water heating for small homeowners’ domestic needs as they eliminated the requirement for a separate hot water cylinder and had a modern room sealed design.

The balanced flue water heater had a Piezo igniter and a permanent pilot. This meant that it didn’t need electricity or batteries.

In these main hot water heaters, the pilot light always stayed on. Because the pilot flame was continually on, this burned up and squandered gas, which was bad for energy bills and the environment.

A few years ago, “Which” consumer magazine conducted a cost analysis that revealed that a pilot light cost an incredible average of £97 per year to run.

The ErP legislation for efficiency with regards to water heaters means that permanent pilot water heaters mean that these types of units no longer meet the required efficiency levels, which is the reason why they are not available anymore.

Electronic ignition models now prevail, and due to the elimination of pilot lights, they end up saving money on running cost.

Now the water heaters must have an electricity supply – just a standard 240 volt – 1 Phase supply.

Main multipoint bf gas water heater

There are some companies offering spare parts for these advanced balanced flue main water heaters, such as the gas isolation valve kit, the thermocouple kit, overheat protection device kit, air vent, and main heat exchanger ( although the price of a replacement heat exchanger is more than a new replacement water heater—i.e., to replace the heat exchanger is no longer viable as the item costs more than a new gas-fired water heater, let alone the cost of a plumber to fit the replacement spare parts)

Should you need to check the gas supply inlet pressure or burner pressure to make sure that the rate of gas is correct, or change the gas isolation valve, then this needs to be done by a qualified gas safe engineer.

It is important to ensure that any suitable service or services such as replacing parts on gas water heaters or gas-fired central heating boilers, should not be attempted by a homeowner or a plumber that doesn’t have the gas safe plumbing qualification.

Main multipoint water heater

A balanced flue system

On demand gas water heaters that employed balanced flues are made up of two pipes with one pipe contained within the other. The outer pipe brings in the fresh air from the outside that is necessary for the combustion process to occur, while the inner pipe serves the purpose of removing the waste gases from your property. Depending on the main instantaneous water heater you purchased, the designed flue system may either go horizontally through an outside wall or vertically through the roof to suit the customers requirements.

The balanced flue model had to be installed on a wall with direct access to the external air environment-see diagram below.

A picture of the balanced flue kit for main multipoint gas water heater – Flexiheat UK

Balanced flue kit details

 

Main also did a fan flued version of this gas water heater, which was designated the main multipoint FF ( fan flue) —this unit is the one that could be vertically or horizontally flued and didn’t need to be installed on an outside wall of the property because of the fan flue system.Again,these fan flue water heaters were a hot favourite with homes or locations that had a big demand for hot water but didn’t want to use a hot water cylinder or storage cylinder.Click here for our dedicated webpage on replacing the obsolete Main multipoint FF water heater

main fan flued multipoint gas fired water heater flue options Flexiheat UK

Main fan flued multipoint – Flue options

 

Hot water instantaneous heater – Balanced Flue Main Heater

So now for the replacement of the Main multipoint water heater in its balanced flue version. Firstly, the dimensions of the unit are

Main balanced flue water heater dimensions from Flexiheat UK

Main bf multipoint water heater dimensions

 

and for our replacement unit – the SF14 Low NOx gas fired water heater with its modern room sealed design.

SF14 on demand water heater dimensions Flexiheat UK

As you can see from the above dimensions, our SF14 Low NOx is smaller in size, yet still has plenty of room for the unit to be maintained and to service, with all the plumbing connections at the bottom of the unit.

lpg tankless water heaters; lpg instant water heaters; liquefied petroleum gas hot water heaters

SF14 – tankless water heaters from Flexiheat UK – Internal picture of the hot water heater

SF14 Product benefits and features

  • Wet chamber copper exchanger that prevents thermal inertia; With large 16mm diameter water ways – so it benefits from very low pressure drops, guarantees lower risks of clogging,greater thermal efficiency, and greater ease of cleaning.
  • Self-diagnostic electronic board;
  • Ease of access and maintenance;
  • Possibility of integration with other renewable energy source (e.g. solar panels)
  • Possibility of remote shutdown;
  • Overheat protection device
  • Reduction of initial overtemperatures with low withdrawals:
  • Degree of electrical protection: IPX4D;
  • Very low NOx emissions, maximum 50 mg / kWh.
  • Modern room sealed design

Because of their sleek, refreshingly modern designs and outstanding reputation for reliability and highest quality this versatile range of water heaters has siting flexibility with various flueing options.

Download the SF14 Low NOx gas fired water heater manual Flexiheat UK

Hot water performance table

The main water heater will produce the following hot water rates, depending on the temperature rise as per the table below.

A table showing the hot water performance of the main multipoint water heater gas fired

Our SF14 water heater model , which has a Domestic maximum nominal heat output of 24.5 kW will produce the following hot water flow rates.

flow rates of our SF14 gas instantaneous water heater

Water heater gas supply

The main multipoint bf water heating unit, as far as we can see from the details, was only available in natural gas, which is category or classification G20 . This is what we refer to as natural gas in the UK, and is the gas that flows from the main gas supply services, or network.

Our replacement for the main multipoint bf or the fan flued models can be powered by either natural gas or propane gas ( LPG ). The LPG version can be fuelled by either a 47Kg propane tank or cylinder , or alternatively by a bulk storage propane tank.

We keep stock of our SF14 low NOx gas water heaters in both gas types in our warehouse , ready to service any immediate order without delay.

Experts in the water heating industry

If you require any more info, correct hot water heating solutions advice, check stock, delivery times, require trade prices or order your replacement for the main multipoint BF water heaters, range then please use the contact us form page on the website, or alternatively feel free to contact our customer service team experts a call on phone number 01202 822221-Flexiheat UK.