12kw Electric Boiler – Electric Boilers

Our 12kW electric boiler can be used for central heating and to produce domestic hot water as well, via an indirect cylinder. Whether the central heating system has standard radiators or underfloor heating systems, our electric boilers can do either or even both. This is electric heating a wet central heating system, with high energy efficiency.

They are the perfect new boiler solution for properties without a natural gas mains gas supply or where flueing requirements prevent the use of gas boilers, oil boilers, or even solid fuel boilers or electric storage heating.

All of our 12kw electric boilers will modulate their output to the heating requirements. This reduces the electricity consumption used and, subsequently, the fuel bills and running costs.

With a 12kW output, these electric boilers can be powered by either a single phase 240 Volt electric (the most common electric supply in UK homes) or a three phase 400 Volt electric supply.

If you buy from a supplier or produce your electricity from renewable energy sources- such as wind energy sources or solar electric energy, then you’re heating and hot water system can be zero carbon rated electric energy.

Electric boilers

Advantages / Benefits at a glance:

• No risk from explosion or carbon monoxide with electric boilers
• High efficiency – 100% – as no heat is wasted in the combustion process(as there is none) and flue or chimney system unlike a gas boiler or oil boiler.
• Gas boiler restrictions mean that a annual safety certificate is required for a rented property with a gas boiler – this is not the case for wet central heating electric boilers, they do not require a annual safety certificate – that’s right no annual safety certificate is required !
• Flexible installation location for the electric boiler -the lack of a flue or a chimney and no fuel tanks allows for more flexibility in the installed position, it also reduces the install cost too. Almost silent in operation too.
• Heating and domestic hot water for your property when used with an indirect cylinder
• Suitable for use on open vented systems or sealed heating systems. When used in older types of open vented systems, you require a minimum head of 8 mtrs on the boilers. Open vented systems are very rare these days, as a sealed heating system offers so many benefits.
• Light weight and compact unit – these wall mounted electric boiler units are light weight, and can be installed in many locations – especially useful in smaller properties – all pipe work connections are located at the bottom
• Flexible installation location with no fuel tanks to install
• Reduce your carbon footprint, you can use solar panels to help power this boiler type
• A long life soft start electric boiler system with zero volt switching – reducing maintenance, service and repair 

12kw Output  

• Which is 12,000 Watts or 40,944 Btu’s of electric output for the wet central heating system.

Energy saving pump with protection against clogging

• During a lengthy boiler shut-off period, regular spinning (once every 24 hours) keeps it from becoming clogged / blocked.

Very quiet operation

• Thanks to the silent triac power switches on these 12kw electric model boilers, they are virtually silent, with no moving parts – zero volt switching.

Smart electronic modulating system with step less regulation

• In low power steps or jumps of 2.5 kW each – the modulating electronic control of this wall mounted heating boiler, will ramp up and down the power steps or levels , to suit the central heating system requirements – be it underfloor heating or standard radiators – this auto heating regulation mode or process ensures reduced energy consumption, as the electric boiler matches the heating output to the demand of the standard radiators or underfloor heating systems, resulting in lower energy bills.

Suitable for Radiators or under floor systems 

• Long life soft start system – which gently starts this boiler type – ensuring that there’s no power surges.

You can use a controller with “OpenTherm +” communication

• These are your “Nest” or “Siri” type of room thermostat, that can be a wireless or internet room thermostat – that you can control your electric boiler from an app on your phone, pad or computer. Allowing you to control your central heating system on the go.

Or you can use traditional ambient thermostats to control the operating temperature

Possibility of temperature regulation according to the room or outside temperature

• Possibility of remote control of the Electric boiler using an SMS message in conjunction with an SMS module ( optional extra)
• Digital control panel with a clear two-digit LED digital display – for heating and hot water.
• Safety switch protection – zero volt switching
• HDO communication – remote switching of the electric supply the boilers to a low rate electricity tariff- very handy if your on an economy 7 type of cheaper tariff electric scheme – saving costs.
• Possibility to control the water temperature output operation with a 0 – 10 Volt signal
• Possibility of producing hot water with an external indirect water calorifier / cylinder when using our three-way valve.
• Top design – with all the components to operate a wet central heating system, with all pipework connections easily accessed as the bottom of the boiler, for easy of installation. The auto air vent is located at the top of the boiler, to ensure it gets the air removed from the boiler, quality products are used throughout.
• Small dimensions of the 12kw output units – greater possibility for installed locations – and lower water content
• Integrated frost protection for this boiler type – to heat the property, and prevent burst pipes
• Auto air vent – to remove any air from the units heat up chamber

Heating only or central heating & hot water

Our boilers can be used heating only or central heating & domestic hot water (DHW) when used with an indirect cylinder (which can be an unvented or an open vented systems), you can provide ample amounts of domestic hot water for your bath, or shower, as well as your dish washing needs. We highly recommend an unvented indirect cylinder, due to the benefits of mains pressure DHW.

At 12kw output you can’t get an 12kw electric combi boiler to produce an adequate flow rate, or adequate water temperatures , especially in the winter period ,when you require warm water the most. A combi boiler is only really a suitable unit or solution when you have a 3 Phase electric power supply as they require the higher Amps to do the job instantaneously.

This is the solution for an electric combi boiler for 15kW or under – using a small indirect hot water cylinder, as with 1 phase / 240 Volt you can’t get an combi boiler to produce enough flow rate to run a bath or shower in the winter period – when you need DHW the most ! quite simply a true electric combi boiler that produces water on demand won’t work at 12kw output or below.

We go into more detail on our 12kW electric combi boiler option more on its own dedicated webpage.

A diagram showing how an electric central heating boiler is connected to a Domestic Water Cylinder – with stainless steel heat exchanger.

1. These electric boilers have an automatic system in them that operates both the heating and the indirect DHW cylinder via a 3 port valve ( no S plan configuration or Y plan configuration should be used)

2. It operates in switching mode

3. DHW always has priority

4. For heating it works at “heating” temperature – various temperature (25 to 80°C etc), can be set and controlled – and you can use Equithermal room thermostat control –

Equithermal control is compensated weather control- the boiler automatically drops the flow temperature relative to the weather conditions – for example on a day when the temperature is 12C outside – and you want 20C inside, the unit works out that you only require 50C to the radiators, and this saves you energy and thus running costs.

The boiler then automatically switches on the pump and heating elements and regulates to the desired temperature for the heating system.

5. For the DHW cylinder – which can be a , the electric boiler heats up to a higher temperature (usually 75-80°C, to heat the DHW cylinder as quickly as possible) – this automatic control closes the heating circuit and opens the DHW heating circuit, switches on the pump and heating elements and heats to a higher temperature (75-80°C) and heats the DHW cylinder very quickly (100 litres in approx. 10 – 20 minutes!)

6. After the DHW Cylinder is heated, it switches to heating (see “4.”)

Why is this set up important?

Because you can have two required temperatures – i.e., the heating side of the boiler, which may be running underfloor heating – which needs a maximum temperature of 45C, of if the electric boiler is compensating the flow temperatures to a radiator system, for example when the thermostatic radiator valves close  – it may have reduced the flow water temperature output to 50 or 60C – This would not be a high enough temperature to heat the indirect DHW cylinder

12kw electric boiler cable size

12 kw electric boiler cable size should be 16 mm2 for use on 1 phase 240Volt electric supply. After installation, all electrical work must be tested in accordance with IEE norms and NICEIC inspection, and a completion certificate must be obtained.

Electric heating company installation

Any electric heating company or a plumber in conjunction with an electrician can install our boilers , there’s nothing special to them and they work with all the standard manufacturer radiators, thermostatic radiator valves, under floor products that standard gas or oil boilers will. Thermostatic radiator valves are used to control individual room temperatures.

More Information / Prices

For more information or prices on our 12kW electric boiler options , then please don’t hesitate to contact our sales team on 01202 822221 or use our email contact form via the contact us tab on the website.

A 100kw boiler is suitable for large domestic and commercial applications, such as installation of a wet central heating and hot water systems for commercial buildings such as schools, sports and health centres, offices and hotels and communal heating schemes. This particular 100kW boiler is ErP “A” label / class condensing technology gas boiler with efficiency up to 108.83 % in condensing mode and is available in either natural gas or LPG.

100kW Gas Boiler – Natural gas or LPG

They are extremely versatile, usually in a wall hung condensing boiler installation although they can be used in a cascade boiler configuration, and we do a full range of time and space saving mounting frames, complete with flow and return headers, gas pipe pipework, low loss header or plate heat exchanger accessories options for primary heating circuit separation.

100kw gas commercial boilers

The unique feature of our condensing commercial boiler, is that they are constructed with two heat exchangers in one boiler casing, if one fails, you still have 50% of your heating demand functioning. You may also service one of the heating units while the other is still functioning, ensuring that your heating water system is never out of commission. This is a significant feature and advantage of these extremely versatile 100 kw wall hung condensing commercial boilers, and unique on the market as far as we know.

Two heat exchangers within our 100 kw gas fired boilers – Flexiheat UK

Servicing the individual boiler heat exchangers, even when used in a common flue heater configuration, is still possible as each heat exchanger has its own flue non return valve installed as standard.

So, what you have is a duty / standby or a duty assist gas boiler set up, but in a one gas boiler set up.

The other huge benefit this gives our 100kw boilers, is the modulation or turn down ratio is 20:1, there’s not another wall hung commercial condensing boiler on the market that has this range performance or ability to match the outputs or heating load required by the system and ensures minimal energy usage.

Best Heat Exchanger – Stainless Steel

Our wall hung condensing 100kw gas fired boilers have a high quality 28mm diameter stainless steel heat exchanger, unlike some of our competition that use an aluminium construction, which many heating engineers regard as inferior. This large diameter ensures the heating water has low pressure drops, guarantees lower risk of clogging, greater thermal heating efficiency, and greater ease of cleaning.

Condensing boiler 100kW – Product technical details

Gas boiler 100kw R1K100 model technical data from Flexiheat UK

Download the Flexiheat Manual for R1K 100 Gas Fired Internal Boiler

28 mm diameter stainless steel water heat exchanger

Large diameter water ways- that prevent clogging and have low pressure drops.

Low Class 6 NOx emissions

Class leading NOx Class 6 emission outputs for boiler 100kw heat output installations.

Control accessories

This gas boiler is fully compatible with BMS systems that are often used in commercial buildings, when installed with our optional 0-10 volt interface card, that fits neatly into the mounting wall boiler.

For installations in large domestic properties, the boiler is fully compatible for connection to an “OpenTherm” controller, such as Nest, Alexa etc, which enables you to control the operation of the heating and hot water functions of the boiler with voice control, an Pad, computer or a phone app.

Dimensions

These commercial gas boilers have compact dimensions, for their heating power output.

R1K100 model dimensions from Flexiheat UK

Ensures minimal energy usage

The condensing mode of this particular boiler is at its maximum efficiency when the return water of the heating system is under the dew point of the by-products of the gas be used to power the boiler, which for natural gas is around 55C. The lower the return water temperature of the heating system installation, the more the boilers will condense. The boilers maximum output and efficiency performance is achieved when the return water is at 30C for the heating system resulting in minimal energy usage.

Multi boiler cascade system

You can cascade our 100kw boiler, with the ability of adding the various boiler outputs from our range i.e., 50kW, 60kW,75kW, 100kW or 120kW output boilers. We can cascade up to 960kW of installed output, with various combinations of boiler outputs to suit your commercial applications. We go into this in more depth on this webpage – Commercial gas condensing boilers

Ultimately this boiler range is extremely versatile, and makes them suitable for everything from large domestic heating to industrial and commercial applications, either as a standalone boiler or used in a multi boiler cascade system either inline or a back to back configuration. They can also produce domestic hot water when used with an indirect hot water cylinder.

More Information / Prices

Four more information or prices on our 100kw boiler / commercial gas boilers in natural gas or LPG, which benefits from condensing technology and is up to 108.83% efficient, then please don’t hesitate to contact our sales team on 01202 822221 or use our email contact form via the contact us tab.

Caravan gas water heater – hot water system

Caravan gas fired hot water heating from Flexiheat UK

A caravan gas water heater provides essential hot water to ensure your caravan or “home from home” has the warm water system to ensure you can shower, at the correct water temperature, and more importantly at the correct hot water flow rate. There’s nothing worse than a poor showering experience as you enjoy your stay in your caravan or holiday home. The other main purpose of caravan water heaters is to provide adequate hot water for dishes or washing up – an area which many of the low-quality water heaters struggle to achieve (more on this further down the page).

Our CE approved gas water heaters for caravans, with the latest innovation provide all the benefits of an instant and unlimited supply of warm water in a cost effective and compact way.

These caravan gas water heaters are meant for static caravans and are not motorhome water heaters.

Water heaters

Firstly, we have to define what a caravan water heater is – the device, heats the domestic hot water up to temperature for such uses as showering, bathing or for the sinks, whether it be hand wash sinks or kitchen sinks – this is referred to as sanitary water or domestic hot water – DHW for short.

So gas fired water heaters for caravans, have to cover the water hot demand for your caravan – Here are some figures and numbers that your water heater has to cover –

A standard showerhead flow rate is 7 or 8 Litres a minute – and the standard temperature is 40 Degrees C

Sink taps – 4 litres per minute capacity– standard type

Cloakroom or basin “spray type taps” – 2 litres per minute capacity- again at 40 C temperature

Bath mixer taps – modern bath taps have an approximate operating demand rate of 12 Litres per minute capacity-  at 40 Degree C.

Kitchen sink taps – 4 to 6 litres per minute but at a heated temperature of 50 Degrees C

Because 50 Degrees C is the temperature required to effectively remove grease from cooking utensils, plates, cups etc.

Thus, it is very important that your caravan gas water heaters can achieve this temperature, with a flow rate to fill the washing up sink in a reasonable time.

So the on demand water heaters heating power or capability of your caravan water heater needs to be suitable to the demands required of it. You get back from swimming in the sea or pool, and you want a nice shower experience from your lpg water heater for static caravan.

Caravan gas hot water heaters

Caravan water heaters come in two main types, electric powered or gas powered

Electric heating element / Electric water heaters

These use electricity to heat the water directly – but come with lots of potential issues that you need to be aware of –

1. The struggle with the capacity to produce warm water instantaneously, as most caravans only have a 1 Phase / 240-Volt electricity power supply – with a maximum draw of 32 Amps – you cannot produce enough thermal energy, from the electric heating element in an electric water heater / electric caravan water heater to satisfy the large capacity hot water demands such as a shower adequately – You need 7 Litres a minute for a standard shower.

2. Another downside is that electricity energy prices are also the most expensive, especially when compared to gas or more specifically LPG (propane) that is the fuel of choice for static caravans.

3. There are electric powered water heaters for boats, or a motor home, with an additional heater element that also include a hot air heater – but these only have a 5 Litre capacity, and take approximately 50 minutes to heat this volume of water from 15C to 60C – which is only enough water for a sink, and nowhere near enough for shower let alone for two people to shower after each other. This is a specialist market, and the truma ultrastore water heater / truma heaters compact heater /carver cascade water heater  are the electric water heater units you want for a vehicle panel van conversions or boat installation.

Gas water heater for caravan – Capacity

Caravan gas water heaters make up the largest part of the requirements for caravan water heaters, as they provide many benefits such as the capacity to provide many litres of heated hot water, as well as fast heating of the water system to an accurate water temperature. They are highly efficient, which saves you money and more importantly work correctly. They produce hot air generated by the combustion process, and these flue gases to give them their official name, must be evacuated from the caravan water heater, via a flue system.

The most popular are –

Propane gas water heater for caravan

With LPG being the predominant gas used on caravan and holiday home parks, where static caravans or static holiday homes are located, this has resulted in LPG or Propane gas water heaters being the most popular water heater for this sector.

The LPG caravan water heaters that we offer are of the highest quality , and heat the water in the most efficient manner and work correctly, our most popular unit is the SFK water heater, which is equipped with a caravan water heaters class leading 16mm diameter heat exchanger water ways, which ensures very low pressure drops, guarantees lower risk of clogging, greater thermal efficiency, and greater ease of cleaning of the equipment . – which is especially important in areas with hard water. Just double check the following map of the UK and Northern Ireland.

Hard water areas of the UK, Northern Ireland and Southern Ireland

Propane Gas (Liquefied Petroleum Gas)

LPG gas or Propane gas as its also known, is the perfect gas to use for caravan water heaters, as the gas is readily available and very common in the UK- other many benefits of the gas are; –

• LPG gas is easy to transport
• The gas is clean burning – the burners have a longer life; hence maintenance is lower for the caravan water heater.
• An effective and efficient gas with direct firing systems as the heat loss is minimal.
• LPG is easy to store, in cylinders or a bulk tank – No spillage risk as opposed to oil heating for example.
• Propane has a low boiling temperature of minus 42ºC, making it perfect fuel for use in lower temperatures and well suited to power a heating boiler or water heater for caravans.

Propane cylinders with gas regulators feeding a static caravan

They can be hidden away from sight like so (regulators hidden as well as pipes)

Caravan on demand water heaters – gas fired

The most popular water gas heaters we do for static caravans is our SF14 model, which has a 24kW output, and is available not only as a propane water heater, but also natural gas if so required. This instantaneous domestic hot water heater produces hot water on demand and gives you an instant and unlimited supply of hot water. This makes this water heating system one of the most efficient, with an “A” rated energy efficiency class and results in you saving money on your caravan water heating needs.

This caravan water heater is an instant water heater or tankless gas water heater.

The dimensional details are –

SF14 LPG water heater from Flexiheat UK

Hydraulic connections – at the bottom of the water heater

Aesthetically pleasing design

SF14 Low NOx from Flexiheat UK – Our static caravan water heater

Download the full manual of the SF14 water heaters for caravans here –

SF14 Low NOx gas fired water heater installation and user manual – Flexiheat UK

Advantages of our caravan water heaters

• Copper wet chamber heat exchanger that prevents thermal inertia
• Reduction of initial water over temperature with low flow rates
• 16mm diameter heat exchanger water ways
• Up to 93.6% energy efficiency
• Room sealed lpg hot water heater – the water heater flue is twin wall – and heater flue kit makes the lpg gas hot water system room sealed.
• Electrical protection level is IPX4D for this equipment
• Ease of access for maintenance / servicing the equipment
• We do a vertical cowl extension, should the caravan the wall ribs prevent you using our standard horizontal cowl extension
• Cost effective water heating equipment for your caravan
• Compact equipment in size
• Water heater white colour
  

  Internal picture of our on demand water heater for static caravans – with large 16mm Copper wet chamber heat exchanger that prevents thermal inertia and blockages.

• Possibility of remote shutdown with our internet / Wi-Fi enabled controllers

Caravan Water Heater Performance

Simply said, the volume of hot water generated by any hot water heater is exactly proportional to the temperature rise of the hot water required. As an example, consider the following:

Showering temperature is 40 Degrees C –

Dish / Kitchen Water is 50 Degrees C – to ensure grease is removed from the utensils

Here is some data on the temperature of the mains cold water in the UK, at different times of the year

Mains cold water inlet temperatures for the UK by region Source – Energy Saving Trust – 2008

So, the required water temperature rise, is known as “Delta T “- this is abbreviated as this sign “ΔT” – And ultimately the lower the temperature rise, the more warm water the device will produce – In the summer when the incoming water is warmer – it will produce more litres, and in the winter, when the incoming water is lower, it will produce less – it’s a simple as that.

Here’s our performance data of our SF14 water heater, at various temperature rises.

Thus, to achieve 40C warm water in the summer, for the majority of the UK, you need a Delta T of 20C – thus our unit produce 15.82 Litres/min – enough to run a bath or 2 showering heads at the same time.

And more importantly, for people who inhabit a static caravan in the winter months – when the delta T is 30C – then you have 10.82 Litres/min – again more than enough to run a standard showering head (which is 7/8 Litres /min) – So we have you covered when you need warm water the most – in the winter!

Frequently asked questions

What is the best water heater for a static caravan ?

Without a shadow of doubt, it is gas fired water heaters – because the flow rates are higher in gas-fired water heaters than electric ones. Also, gas water heaters are much less expensive to operate than electric water heaters. They are more expensive to purchase than an electric water heater. However, based on energy savings, gas water heaters typically pay for themselves in roughly a year.

Static caravan lpg water heaters ?

Static caravan lpg water heaters are by far the most popular water heater used in static caravans , as lpg is readily available, and cheaper than using electricity to heat your warm water requirements.

Caravan Gas Fired Water Heater

We carry stock, and use a small pallet service to deliver anywhere in UK, Northern Ireland and Southern Ireland.

Should you require any more information or prices on the best caravan gas water heater / lpg water heater for caravan, then give our sales team a call on 01202 822221.A full inc vat invoice is supplied for all items supplied. For our latest news follow us on Facebook or Twitter for our latest special offers.

LPG Water Heaters / Propane water heater range

LPG (Propane Gas) Water Heaters / Instantaneous propane water heater range from Flexiheat UK

Water Heaters LPG Fired

LPG gas water heaters– What are they, and what are the benefits? An LPG (Liquefied Petroleum Gas) water heater is a gas fired water heater that heats domestic hot water instantaneously to multiple points around your home or building. This lpg hot water heater range allow you to connect the energy efficient water heaters to a number of hot water outlets throughout your domestic properties or home or even a commercial building and provide accurate hot water temperature and continuous flow rates from these gas fired water heaters.

They are often called a LPG instantaneous water heater,instantaneous propane water heater, LPG tankless water heater ,LPG on demand water heater or even a LPG gas water boiler.

On demand or continuous flow propane gas water heater?

This type of lpg water heater, provides a simple and proven solution for providing instantaneous domestic hot water on demand, without the need of an indirect cylinder and a propane gas boiler. This liquefied petroleum (LPG for short) gas fired water heaters, which are available in propane (LPG) or as a natural gas water heater are simple, with high energy efficiency and clean combustion. These gas fired water heaters when powered by propane are often called lpg tankless water heaters and provide many benefits with higher energy efficiency than storage gas water heaters.

These gas water heaters are also an energy saving solution to more traditional domestic hot water storage systems, as they only heat and deliver hot water when its required. These facts have made the lpg flow water heaters not only the customers propane water heater of choice, with great user comfort, to deliver hot water on demand in the most economical and energy-efficient method possible, but also the plumbers / heating installers choice as well.

BioLPG Fuel

BioLPG, additionally referred to as biopropane or renewable propane, is an exciting, ecologically friendly alternative to standard LPG or natural gas. It is both renewable and sustainable, and it may reduce your carbon footprint by up to 90%. BioLPG is identical in its use to conventional LPG so is a ‘drop-in’ solution.BioLPG is inexpensive, energy efficient, and convenient replacement for standard LPG Gas (Propane) and our propane instant hot water heater range will run on this fuel.

Click here for more information on BioLPG

Propane Water Heater? What are the benefits

• High performance mains water pressure to all warm water outlets with our extensive range of lpg hot water heaters
• ErP Class “A” energy efficiency for your domestic hot water requirements – Save money and save the environment with our lpg instant water heater range
• LPG tankless hot water heater -no cylinder required -Tankless lpg water heater systems are far more efficient than storage cylinders and boilers.
• Low NOx or condensing LPG fired water heater options – less polluting and better for the environment
• High hot water flow rates of up to 29 litres per minute with a hot water temperature water rise of 33 Degrees C
• We can supply Propane gas or Natural gas fired versions at great prices.
• Internal (indoor lpg water heater) and externally (external lpg water heater) mounted gas fired water heaters are available

External or outside gas fired water heaters from Flexiheat UK

• Modular – Flexibility of usage – multiple heaters can be used to supply greater hot water demands, in cascade.
• These high energy efficiency propane water heaters are suitable for domestic and commercial applications such as domestic properties, cafes, pubs, restaurants, offices or shops
• These propane gas water heaters are simple to install and maintain in any small or limited space location.

Sometimes you can’t use instantaneous water heaters due to a peak demand and must use a storage volume to accommodate this – these are detailed here – gas hot water tank or cylinder which are available in LPG (Propane) or natural gas.

LPG DOMESTIC HOT WATER HEATERS

Our range of  instantaneous tankless water heaters, are available in either natural gas or as a propane gas water heater ( LPG Gas). LPG (Liquefied Petroleum Gas) is a gas that exists in a liquefied form, and is a very popular fuel for heating homes, and also in commercial applications such as caravan parks, leisure parks and any other categories where mains gas supply is not available.

The most common LPG (Liquefied Petroleum Gas) gas used for water heaters is propane, as this gas is ideal for outdoor use, as it is not affected by cold weather conditions that we can have in the U.K and Northern Ireland.

This gas has a classification of “G31 Propane”, and can either be stored in larger tanks or mobile cylinders.

Should you wish to run your flow water heaters on (LPG) propane gas, we would recommend a bulk gas tank, however you can run these units of gas cylinders for example – a 47kg propane cylinder maximum continuous off take rate is per hour 32.94 KW, for heaters rated above this input, your LPG hot water heating system will require more than one and thus automatic changeovers valves sets are used or a bulk lpg tank.

For the above reasons, our LPG gas water heaters are very popular in camping and caravan sites as caravan gas water heaters, for shower blocks or restaurants and with sports / leisure facilities, such as football and rugby clubs, again for showering facilities, as these water heaters can be used in multiples or in a cascade configuration to give its official name.

CONDENSING OR NON-CONDENSING LPG GAS WATER HEATERS?

For gas fired water heaters to work correctly and condense, the water coming into the contact with the heat exchanger, must be under the dew point of 54°C or lower for propane gas– the maximum incoming cold water temperature, even in the height of summer is 20 Degrees C for the UK, meaning you’re going to have the water heater operating in the condensing mode all year round! and benefit from high energy efficiency.

Thus, this gas fired condensing water heater process will deliver hot water with up to 105% net thermal efficiency, resulting in significant energy savings when compared to conventional non-condensing gas fired water heaters.

Ultimately, condensing propane water heaters just make perfect sense. They are slightly more expensive than non-condensing versions, but that price is warranted with lower running costs and lower impact on the environment.

We do however, produce one unit, which is a non-condensing water heater for the cost conscious, our “SF Low NOx Evolution” model, which is available with a power output of 24 kW. This has been a very popular model for the domestic water heaters/ caravan water heater market, although most consumers can now see the benefit of the condensing hot water heaters, with the UK market moving towards this type.

Our range of instantaneous tankless water heaters, are available in either natural gas or LPG Gas. LPG (Liquefied Petroleum Gas) is a gas that exists in a liquefied form, and is a very popular fuel for heating homes, and also in commercial applications such as caravan parks, leisure parks and any other categories where mains gas is not available. We have many customers who just want to supply just one bathroom or multiple bathrooms – which we can achieve.

The most common LPG (Liquefied Petroleum Gas) gas used for water heaters is propane, as this gas is ideal for outdoor use, as it is not affected by cold weather conditions that we can have in the U.K and Northern Ireland.

This gas has a classification of “G31 Propane”, and can either be stored in larger tanks or mobile cylinders.

Should you wish to run your lpg gas water heater on (LPG) propane gas, we would recommend a bulk gas tank, however you can run these units of gas cylinders for example – a 47kg propane cylinder maximum continuous off take rate is per hour 32.94 KW, for heaters rated above this input, your LPG hot water heating system will require more than one and thus automatic changeovers valves sets are used.

For the above reasons, our LPG gas water heaters are very popular in camping and caravan sites, for shower blocks or restaurants and with sports / leisure facilities, such as football and rugby clubs, again for showering facilities, as these water heaters can be used in multiples or in a cascade configuration to give its official name.

FACTORS TO CONSIDER WHEN SELECTING / SIZING YOUR PROPANE WATER HEATER

There are three important factors to consider when selecting the correct water heater for your requirements.

The standard water temperature for bathing or washing is 40 Degrees C

In essence, it’s just a simple matter of the law of physics – the larger / more powerful the lpg water heater, the greater the flow rate of hot water. This is especially true, when in the winter months, as the mains cold water entering temperatures drops, and this is an important factor to consider in UK.

Thus, the amount of warm water the lpg gas water heater will produce and directly related with the temperature rise that the water heater is required to achieve (more on this in point 2). You basically need to cover the flow rates of your hot water appliances, with your usage patterns.

Flow rates

Kitchen sink taps – 4 to 6 litres per minute

Sink taps – 4 litres per minute – standard type

Basin / cloakroom “spray taps” – 2 litres per minute –

A standard shower head has a hot water demand of 7 or 8 litres a minute,

Bath mixer taps – modern bath taps have an approximate demand rate of 12 Litres per minute

So be adding all of your potential hot water outlets, then applying a diversity factor (a factor that not all of the hot water outlets will be used at the same time) you can calculate your hot water demand

Water Heating – Temperature rise

The temperature rise that the gas water heaters have to achieve. This is also known as T ° variation or delta T which when abbreviated looks like this “ΔT”. Quite simply the amount of hot water produced by any water heater, is directly affected by the temperature rise of the hot water required. An example of this is –

If you set the hot water temperature to 35 ° C and the cold water entering the multipoint gas water heater is 15 ° C, then you have a variation of temperature or delta T of 20 ° C (35 ° Degrees C minus 15 ° Degrees C). Alternatively, if the appliance was set to a desired hot water temperature of 40 ° C, then the temperature rise or delta T would be 25 ° C (40 °- 15°) and thus the flow rate achievable changes.

Mains cold water temperature for the UK

The incoming mains cold water temperature for the UK, for various regions is as follows –

We have two sources of information here –

Mains cold water inlet temperatures for the UK by region Source – Energy Saving Trust – 2008

Or the blue line on the following chart

Please see the blue line for the average mains cold water temperature for the UK over a 12 month period

The above chart shows the coldest water temperature in January at around 5 Degrees C – Source TUV

Please use whatever data your comfortable with

LPG Fired Water Heater Range

We do both a domestic LPG water heater and a commercial heater range, both of which have great temperature control, energy efficiency and capacity.

Unlike a lot of our competitors, we are more than proud to publish our performance data at many different temperature increases, as there may be applications – such as commercial kitchens or other applications which require the water to be produced at higher temperatures, such as industrial hot water systems.

The first and smallest unit is our SF14 propane tankless water heater model which is a 24kW non condensing low NOx model domestic water heaters- this unit benefits from-

• 16mm diameter heat exchanger water ways – the largest we know of on the market (except our condensing lpg units – which are an incredible 28mm in diameter) this size ensures very low pressure drops, guarantees lower risk of clogging, greater thermal energy efficiency, and greater ease of cleaning. – especially important in areas with hard water – and all this with great prices on our gas fired water heaters.
  

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

   

• Wet chamber copper heat exchanger that prevents thermal inertia
• Reduction of initial water over temperature with low flow rates
• Very low NOx emissions, maximum 50 mg / kWh – better for the environment.

DHW performance for the SF14 propane gas water heater is –

We class the Red figure – as worst case winter performance , and the Yellow figure as the height of summer performance

SF14 Low NOx water heater hot water performance by Flexiheat UK

The SF14 model are our most popular domestic water heaters and are the perfect solution to the hot water requirements for domestic properties.

Please note due to recent regulation changes the SF14 gas water heaters can only be used in domestic water heating applications for houses or flats etc , if the water heater is in a commercial water heating application, the unit must be a condensing water heater – see this dedicated webpage for further information.

The next range is our condensing lpg instantaneous domestic hot water heaters , which are the most efficient that you can find on the market- there are 3 models in this range, and two different options. All unit will require a condensate drain

SFC range – for direct feed to the hot water outlets (the most common application)

SFK (for dhw recirculation systems) with an in inbuilt pump, the larger 50 water heater model is only available with the inbuilt pump, its up to you whether you use it or not.

The performance is the same for the direct feed and pumped versions of our propane tankless hot water heater.

28kW Propane tankless water heater model performance data

SFC and SFK28 LPG Domestic hot water performance by Flexiheat UK

Internal versions manuals

Download the SFC28 Internal condensing water heater (no recriculation pump) manual from Flexiheat UK

Download the SFK28 Internal condensing water heater (with recriculation pump) manual from Flexiheat UK

External version – designated the “Rain” – SKF – this has the inbuilt pump – which is required for frost protection – the unit fires up when the external temperature reaches 5C , and the pump pushes the water around the heat exchanger to prevent freezing of the water heater.

Download the SFK28 “Rain” External condensing water heater (with recriculation pump)  manual from Flexiheat UK

34kW Propane tankless water heater model performance data

SFC and SFK34 LPG Domestic hot water performance by Flexiheat UK

Internal versions manuals

Download the SFC34 Internal condensing water heater (no recriculation pump) manual from Flexiheat UK

Download the SFK34 Internal condensing water heater (with recriculation pump) manual from Flexiheat UK

External version – designated the “Rain” – SKF – this has the inbuilt pump – which is required for frost protection – the unit fires up when the external temperature reaches 5C , and the pump pushes the water around the heat exchanger to prevent freezing of the water heater.

Download the SFK34 Rain External condensing manual from Flexiheat UK

50kW Propane tankless water heater model performance data

SKF50 LPG Domestic hot water performance Flexiheat UK

This 50kW gas water heater only comes with a pump– which can be used or not used -, depending on your jot water system requirements i.e. direct or DHW recircualtion system.

Download the SFK50 Internal condensing water heater (with recriculation pump) manual from Flexiheat UK

Flue Options

We do various flue options, the most common is a co-axial , which takes the combustion air from outside , and flue gas from the device to the outside – making these units room sealed

The most common flue kit is our horizontal co-axial flue kit

Horizontal Flue Kit – Co-axial room sealed by Flexiheat UK

Or the vertical flue kit

Vertical Co-axial flue kit from Flexiheat UK

Using a split flue system, we can achieve flue routes of up to 60 metres for our lpg hot water heater range.

LPG tankless water heater UK

We carry stock, and use a small pallet service to deliver anywhere in UK and Northern Ireland.

For more information, advice or to find /learn more on our energy efficient hot water heating units, which are lpg gas water heaters / propane gas water heaters with indoor or outdoor versions at great prices and quality, or for delivery times, to place an order, get prices then email us at sales@flexiheatuk.com or give our sales team a call on 01202 822221.