LPG Boilers Explained & Reviewed

LPG Boilers Explained & Reviewed

There are over 4 million UK residential properties not connected to the gas grid. For many of these homeowners, their boilers are powered by electricity and oil – which are both much more expensive to run than a gas boiler.

There is, however, a growing market for LPG boiler installations for properties with no mains gas supply.

In this article, we take a look at:

• what an LPG boiler is
• whether you should have your tank installed above or below ground
• LPG boiler pros
• LPG boiler cons
• Important LPG boiler terms
• how much it costs to run an LPG boiler
• how the cost of running an LPG boiler compares to other types of boilers
• what the 3 types of LPG boiler are
• what size of LPG boiler you will need for your property
• energy efficiency and LPG boilers
• LPG boiler manufacturer rankings as measured by Trustpilot
• the HomeSage boiler ranking system and how it works
• the 10 cheapest LPG combi boilers
• the top 5 combi LPG boilers as ranked by HomeSage
• the 10 cheapest LPG system boilers
• the top 5 LPG system boilers as ranked by HomeSage
• LPG regular boilers currently on the market
• currently available LPG boilers as ranked by HomeSage
• how much it costs to install an LPG boiler and how long it takes

What is an LPG boiler?

LPG stands for liquified petroleum gas.

This is a natural hydrocarbon fuel made of propane and butane gases and it can be used to power a boiler in order to provide hot water and central heating for a property. 

LPG is used as a fuel because it burns relatively cleanly thanks to its relatively simple chemical structure. 

An LPG boiler can be an alternative choice for a property not connected to the gas mains grid because:

• one produces less carbon than an oil burner and 
• one may also be combined with renewable energy sources such as solar panels. 

LPG boilers require a separate tank to store the fuel.

LPG tanks are usually situated in your garden and they can store between 1,000 – 2,000 litres of fuel before being refilled periodically by a tanker delivered directly to your property. 

You can buy an LPG boiler or choose to adapt a standard gas boiler into an LPG boiler using a conversion kit.

In this article, we compare and review LPG-exclusive boilers and not boilers which can be converted.

Should my tank go above or below ground?

This depends on your property size and the size of the storage tank you require.

Underground tanks take more time and money to install and they need to be at least 3m away from any property.

You will also need to decide if you want to install it horizontally or vertically but, again, some restrictions may apply.

If you opt to have your LPG tank above ground, usually installation is much quicker and cheaper.

It can be installed on a concrete or prefabricated base and, much like the underground tank, it needs to be at least 3m away from any property such as a house or garden shed.

Also, above ground installations should be performed in an area free from clutter and overhead cables. 

Your boiler engineer will be able to advise on which option may be more suitable for your property and budget.

LPG boiler advantages

Once you have installed your new LPG boiler there are many advantages to enjoy, including:

• Cleaner fuel emissions – although this type of fuel does still emit carbon, it’s around 15% – 20% less than would be produced with an oil burner so it is the more environmentally friendly of the two
  
• High efficiency levels – usually, LPG boilers are a minimum of 90% efficient, which means only 10% is wasted as lost energy
  
• Cheaper to buy than an oil burner – if you’re not on the gas grid, an LPG boiler is a cheaper purchase than an oil burner as starting prices can be as low as £350, whereas oil burners can be closer to the £1,000 mark
  
• Compact in size – usually these boilers are fairly small so can fit in your home with ease, as well as being quieter than oil fuelled boilers
  
• A wide selection of model choices – LPG boilers are popular in the UK and many leading manufacturers have a good range to choose from so you have a lot of options to consider when you’re shopping around.

LPG boiler disadvantages

As we are an impartial website, we’ve also listed the cons of choosing an LPG boiler so you can make an informed decision:

• They require an additional storage tank – so you need to cover the cost of purchasing this and installing it which can add considerably to your bill
  
• Fuel cost is higher than oil – although prices have dropped in recent times, the cost of a unit of energy is still higher than natural gas and oil and it’s unclear as to how this will change in the future
  
• You need to keep a check on your LPG levels – to avoid running out of fuel, you need to be aware of your consumption levels. 

Some LPG delivery companies track your usage and deliver automatically but running out of fuel is a potential issue you should be aware of.

Important terms to know

Unless you have had experience replacing or researching boilers before, the technical terms you need to know may be brand new to you. 

Just in case, we’ve written a quick description of the keywords you need to know about when researching your new boiler. 

Flue

A flue is a pipe or duct which extracts the waste gases from the boiler itself.

This is important because it makes sure the potentially harmful chemical waste isn’t being pumped into your home but rather siphoned off outside through a pipe in the wall.

Clock

The clock on the boiler allows you to set the times for your central heating and hot water requirements.

Your clock can be analogue or digital depending on the model of the boiler.

They are useful so you can pre-set your requirements for heating – for example, to go on 15 minutes before you get up and to switch off when you usually go to bed.

Filter

Boilers are working bits of machinery and, as there is water running through them, sometimes they get clogged up by rust and debris. 

A filter maintains your boiler’s working capacity by catching this sludge before it enters your hot water system.

They often use magnetism to attract these rust particles. A good filter means that your boiler won’t slow down or break after a few years of consistent use.   

Scale reducer

Scale reducers can either be magnetic or electrolytic.

A scale reducer combats the build-up of limescale inside your boiler, much like what happens inside your kettle.

Magnetic scale reducers act like a water softener to collect limescale causing minerals before they stick to the metal work, whereas electrolytic scale reducers alter the structure of the limescale to stop it sticking. 

Storage tank options and costs

With LPG boilers there are three different options for the fuel storage tanks:

• An over ground tank in your garden
  
• An underground tank in your garden
  
• Two to four bottles that can be stored in a cabinet at the side of your house.

The three main suppliers of LPG gas in the UK are Calor, Avanti and Flogas and costs vary considerably depending on the size of storage tank you require and its installation location. 

For a 1,200 litre over ground storage tank, it would cost £550 to install from Calor and £400 from Flogas.

For a larger, 2,000 litre over ground tank from Avanti it would cost £900.

It’s worth noting that these companies also have a minimum contract requirement of 2 years .

There are also installation costs and, on many contacts, the tank will remain the property of the company which installs it. 

How much does it cost to run an LPG boiler?

LPG is slightly more expensive than oil to run at 65p per litre as opposed to 55p per litre for oil.

With this in mind, LPG boilers cost approximately 6.5 – 7.5p/kW to run so per year with an average use of 12,000 kWh, it would cost you around £800 as an estimation. 

How does the cost of running an LPG boiler compare with other types of boiler?

As you may know, there are four main options when it comes to choosing how to fuel your home heating boiler system. 

Here, we have provided you with a breakdown of the costs and as you can see, the mains gas is the cheapest option with electricity being the most expensive.

The three types of LPG boiler

LPG is the fuel that powers your boiler but there are still three different types of boiler system to choose from.

Please read our descriptions below to find the most suitable central heating system for your needs. 

Combi LPG boiler

Combi boilers draw their fuel from the LPG tank to heat water directly from the mains supply as it passes through the boiler and around your property to the hot taps and radiators. 

It works by heating the water almost instantly using a heat exchanger.

This means that, as soon as someone turns the hot tap on, they have access to hot water and it never runs out. 

They are usually compact, wall-hung units which don’t need an extra water storage tank although, if you are using LPG, you will require the fuel storage tank in your garden. 

The only issue with combi boilers is that the water pressure can drop if more than one person uses it at one time.

This can be problematic especially in areas of low water pressure so they may not be suitable in properties that have high hot water demands.

Regular LPG boiler

Regular LPG boilers are also known as traditional boilers and they require an additional water storage tank in your loft. 

This water is piped into the boiler before being heated up and stored for your use resulting in strong water pressure regardless of how many people are using it at one time.

However, once the hot water has run out, you will need to wait for a new batch to be heated which can be inconvenient. 

These systems work well in larger, older properties with high hot water demands which already have the pipework installed. 

System LPG boiler

System boilers fuelled by LPG are similar in size to regular boilers and they are also usually floor-standing units that take up more room than combi boilers. 

They don’t require the water tank in the attic.

Instead, they heat water internally and store it too, the result of which is a reliable source of water with good pressure, 

However, as with regular boilers, they do require time to heat up again unlike combi boilers.

What size of LPG boiler is suitable for your property?

Deciding on the right LPG boiler for you greatly depends on the output (kW) level required.

Your two main goals should be to achieve maximum energy and cost efficiency and to make sure your water needs will be met.

All boilers have an output level and this tells you the power of the boiler as well as how much it will cost to run.

To work out how much your boiler will cost to run, you simply multiply the output by the cost of the unit of energy.

So, for example, a 20kW boiler fuelled by LPG (priced at 7.6p a unit) would be 20 x 7.6 = £1.52.

It also is important to choose a boiler with an appropriate level of output for your property size. 

As you can see from the table below, the larger your property and number of radiators and bathrooms the higher the output needs to be. 

The standard of insulation you have in your property also plays a part in the output you may require because newer properties have better insulation so can manage on a lower output. 

If you have a pre-1900 property it is likely to have a poor level of insulation.

For example, if you live in a two-bed home from this period, you may require a boiler with an output of at least 18kW.

However, for the same size property which is a post-2000 build, an output of 13kW would suffice. 

Properties that have been built since the turn of the new millennium will most likely have high levels of insulation.

Therefore, for example, a 4-bed home would only need a 16kW boiler whereas the same size home build over 50 years ago may require 20kW or higher. 

Always consider energy efficiency when selecting an LPG boiler

Reducing your carbon footprint has never been so important but high levels of energy efficiency also makes sure that more money stays in your back pocket, too.

The higher the energy efficiency of your boiler, the less it will cost to heat your home as less energy is wasted by the boiler itself simply performing its job correctly. 

UK LPG boiler brands – customer rankings

Here we have the six main manufacturers of LPG boilers in the UK as of 2020 and listed them as per their scores and reviews on the Trustpilot website.

The HomeSage boiler ranking system

Here at HomeSage, we have developed our own unique online boiler ranking system to help you make an informed decision on your new LPG boiler.

Our system takes a variety of elements into consideration in order to give a fair run down of the available boilers on the market.

And, as we are an impartial site, we have also included genuine customer reviews from Trustpilot users who have had a first-hand experience of that particular manufacturer or installer. 

Our scores take into consideration the following factors and features:

• the type of fuel the boiler uses (as gas is the cheapest option by far, each gas boiler gets a maximum score for this automatically which pushes LPG boilers down in the ratings),
• the length of the warranty provided as standard
• the energy efficiency rating of the boiler, and
• the amount of customer reviews and average company rating from Trustpilot.com

The 10 cheapest LPG combi boilers

At time of writing, there are 20 LPG combi boilers on the market in the UK, with an average price of £946 before tank installation costs are applied. 

This table is the list of the top 10 cheapest LPG combi boilers.

5 top HomeSage ranked LPG combi boilers

The HomeSage top 3 LPG boilers according to our scoring system was dominated by Baxi models. 

Vaillant, Vokera, and Ideal models all finish in the top 10 with strong overall scores. 

Baxi Duo-Tec 28 LPG (ErP) Combi (89.12%)

This boiler comes with a 7-year warranty as standard so you can have extra peace of mind.

The dimensions are 780mm x 450mm x 345mm so it is slightly on the larger size for a combi boiler.

It is one of Baxi’s most popular models for LPG and has a great energy efficiency rating of over 93%.

Baxi 624 LPG (ErP) Combi (87.36%)

A slightly smaller combi boiler from Baxi is the 624 LPG (ErP) combi which measures in at 700mm x 290mm x 285mm. 

It is a wall hung unit finished in a gloss white with two control knobs and a digital display reader.

This boiler comes with a 7-year warranty and has a low lift weight of under 30kg for easy installation. 

Baxi 630 LPG (ErP) Combi (87.18%)

This is the same Baxi which came in second place but with a higher output.

The 630 LPG has the same dimensions of 700mm x 290mm x 285mm and 7-year parts and labour warranty.

It fits easily behind a standard kitchen unit for seamless integration into your home.

It also benefits from the EasyFill system which means less call outs to the gas engineers as the pressure is self-regulating. 

Vaillant ecoTEC Plus 832 LPG (ErP) Combi (83.98%)

This Vaillant boiler is hand-built in Derbyshire and it benefits from a standard 5-year guarantee that can be extended to 7-years if installed by a Vaillant approved engineer. 

It achieves good levels of energy efficiency even during periods of low emissions as it features continuous modulation and combustion control via a multi-sensor system. 

It measures 720mm x 440mm x 338mm.

Vaillant ecoTEC Pro 28 LPG (ErP) Combi (81.14%)

The EcoTech range from Vaillant comes with a slightly lower 2-year warranty but still features the fully modulating low NOx burner and fan for maximum energy efficiency. 

This boiler measures 720mm x 440mm x 335mm, has the Quiet Mark seal of approval and has also been recommended by Which? in their Best Buy category.

The 10 cheapest LPG system boilers

At time of writing, there are 10 system LPG boilers available in the UK and they have an average price tag of £1,130 excluding installation and the fuel storage tank. 

5 top HomeSage ranked LPG system boilers

Baxi 624 (ErP) LPG (86.94%)

This boiler is built in the UK Baxi factory using high quality internal components and it comes with a 7-year warranty for parts and labour providing you follow the terms and conditions.

It measures 700mm x 390mm x 285mm so a fairly standard size and it is finished in a traditional gloss white durable casing. 

It is compatible with the market leading Megaflo Eco Cylinder for properties needing extra power. 

Vaillant ecoTEC Plus 618 LPG (ErP) (83.75%)

This boiler comes with a 5-year guarantee as standard which can be increased to 7-years when installed by a Vaillant Advance engineer, or 10-years if you opt for fitting with the Vaillant Boiler Protection Kit.

It measures in at a slightly larger size of 720mm x 440mm x 338mm and it has a stylish finish with a drop-down control cover.

It benefits from the Quiet Mark seal of approval so no bumps or bangs will disturb you whilst in use. 

Vaillant ecoTEC Plus 630 LPG (ErP) (83.24%)

The Vaillant ecoTEC Plus 630 LPG boiler measures a standard 720mm x 440mm x 372mm.

It comes complete with a 2-year warranty that has the option of being extended to 7-years during installation by an approved Vaillant engineer. 

It benefits from an easy-to-use installation wizard so getting your boiler up and working shouldn’t be difficult or disruptive for you, and it also is accredited with the Quiet Mark tick of approval. 

Ideal Vogue S15 GEN2 LPG (79.74%)

Designed to be efficient and reliable, the Ideal Vogue S15 GEN2 LPG boiler comes complete with an impressive 10-year warranty for extra peace of mind. 

It measures 740mm x 445mm x 330mm and it benefits from a low lift weight of 30.7kg.

It has a backlit 3.5 inch LED display so is easy to read even in dimly lit cupboards or spaces.

Ideal Vogue S18 GEN2 LPG (79.64%)

The next model up is the Ideal Vogue S18 GEN2 LPG which features a slightly higher output of 18kW but the same fantastic 10-year warranty. 

Weighing slightly more than the lower output model at 31.5kg it still has a low lift weight for easy installation and this range of boilers also benefit from frost protection and quick installation as it is a single-piece unit.

This boiler measures 740mm x 445mm x 330mm. 

LPG regular boilers currently on the market

At the time of writing this article, there were 2 LPG regular boilers available in the UK and they are listed below.

Vaillant ecoTEC Plus 424 LPG (ErP) (86.13%)

This Vaillant boiler comes with a 5-year guarantee that can be extended to 7-years upon installation by a certified Vaillant engineer. 

It is a wall-hung unit that measures 600mm x 375mm x 320mm so it is extremely compact and can be tucked out of sight inside a kitchen cabinet if required.

It has an easy to use digital display panel concealed by a slick drop down cover and the boiler itself features a smart chrome trim. 

Vokera Easi-Flo LE 30kw LPG (75.58%)

This boiler has a standard 2-year warranty included and benefits from easy installation and set-up. 

It measures 640mm x 400mm x 246mm and has a digital display with push buttons for ease of use. 

It also benefits from a keypad lock function to avoid any accidental setting tampering and can accept pre-heated water with an additional solar integration system. 

How much does it cost to install an LPG boiler?

Typically, it will cost around £150 – £200 per day for an engineer to come out and fit your boiler.

This doesn’t include the cost of the boiler itself which can vary substantially, nor does it include any costs for building work or preparation to your property if the new boiler can’t be easily fitted.

Installing an LPG boiler can take anywhere between 1 and 3 days but it’s best to ask your boiler installation company for their estimate before you commence work just to be sure.

Save up to 54% on the cost of your installed LPG boiler

We offer a completely free, no obligation service that could save you up to 54% on the cost of the supply and installation of a new LPG boiler for your home.

Simply fill in our online form today and we will get in touch with three or four local, reliable and Gas Safe regulated engineers to quote you competitively for your boiler installation requirements. 

Even if you decide not to go ahead with any of the options from the local firms, the service is 100% free for you and there are no penalties if you change your mind. 

Related articles

• Best electric boilers
• Best oil boilers
• Top boiler manufacturer reviews