Choosing the right boiler is essential for keeping your home warm, energy-efficient, and cost-effective. At JPS Plumbing, Gas, and Electrical, wChoosing the right boiler is essential for keeping your home warm, energy-efficient, and cost-effective. At JPS Plumbing, Gas, and Electrical, we work with a wide range of boilers. Time and again, Vaillant stands out for its quality, reliability, and smart technology.
A Vaillant boiler is a smart investment for your home, offering high-quality components, exceptional energy efficiency, and quiet operation. With advanced modulation technology, smart thermostat compatibility, and excellent warranties, Vaillant ensures reliable, cost-effective heating with strong after-sales support.
While we are not tied to any particular brand, Vaillant is the one we tend to recommend the most. And as Vaillant Advance Mastertech installers, we understand the range inside out.
In this article, we’ll explore why a Vaillant boiler is a great investment, highlighting its key benefits and range of options to help you make an informed decision.
Watch our founder, Jamie, talk more about Vaillant boilers on our YouTube channel.
What are the benefits of a Vaillant boiler?
If your existing boiler is starting to let you down, Vaillant gas boilers are a strong choice for more comfortable and reliable heating.
- Reduced energy bills – An older boiler can use more gas than it needs to, especially if it is struggling to heat your home efficiently. Modern Vaillant boilers have a high efficiency rating, meaning lower gas bills and less wasted energy.
- Reliable heating – A reliable boiler gives you real peace of mind during the colder months. Vaillant is known for dependable performance, helping to keep your home comfortable through everyday use, from busy mornings to chilly evenings.
- Quiet operation – If your boiler is fitted near a bedroom, kitchen or living area, noise matters. Vaillant boilers are designed to run quietly, and selected models have Quiet Mark accreditation.
- Smart technology – The latest Vaillant boilers can work with smart controls, so you can manage your heating remotely from your phone. You can adjust the temperature, adjust your heating requirements around your schedule, and avoid heating an empty home.
- Durable quality – Vaillant boilers are built with high-quality components, such as steel heat exchangers on selected models, giving you a reliable heating system for years to come.
- Excellent warranties – A new boiler is a big investment, so it helps to know you are protected if something goes wrong. Many Vaillant boilers come with generous guarantees when installed by an approved installer, giving you added reassurance.
- UK manufactured – Johann Vaillant founded the company all the way back in 1874, and it’s since become one of the UK’s market-leading boiler brands. While the company is still German-owned, the majority of Vaillant boilers supplied to the UK are manufactured at their award-winning plant in Belper, Derbyshire.
Vaillant boiler guide
Vaillant offers a wide range of condensing boilers to suit different homes, heating systems and hot water needs. This includes combi boilers, system boilers and heat-only boilers (also known as open vent boilers), with each type designed for a different kind of household. For more information, see our other article about boiler types.
We’re Vaillant boiler installation experts and have a vast amount of experience installing them. Here is an overview of key features of the Vaillant gas boiler range.
Combi boiler range
Combi boilers provide both heating and hot water and require minimal space, making them great for smaller homes.
- ecoTEC exclusive with Green iQ combi
- ecoTEC plus
- ecoTEC plus combi store
- ecoTEC pro combi
- ecoFIT pure combi
System boiler range
System boilers store hot water in a cylinder, usually located in the loft, and are suitable for homes with multiple bathrooms.
- ecoTEC exclusive with Green iQ system
- ecoTEC plus system
- ecoFIT pure system
Heat-only boiler range
Also known as open-vent boilers, conventional boilers and regular boilers. They work with a cold water tank and hot water cylinder, perfect for older systems or high-demand households.
- ecoTEC plus regular
- ecoFIT pure regular
Let’s put these boilers under the microscope…
ecoTEC exclusive with Green iQ combi
This is Vaillant’s highest-specification boiler, made with stainless steel heat exchangers and brass hydroblocks. We can give a 10-year warranty on this model.
It is available in two different outputs:
- 35kW boiler, modulating down to 3.9kW
- 43kW boiler, modulating down to 4.8kW
The way these boilers modulate right the way down makes them incredibly energy efficient.
What ‘modulating down’ means is that the boiler will work itself out and use as little energy as it needs to heat the house. For example, if the house only needs 5kW of heat per hour, that’s what it will run at. It won’t run at its maximum 35kW. This is sophisticated technology compared with old boilers that used to be either on or off – in this case, all 35kw, or nothing!
Modern boilers are designed to run for longer periods of time but at a lower kW rating, which is more energy efficient.
So, as this is a combi boiler, we also need to look at its hot water performance.
We look for the ’35-degree rise’. For this model, the numbers are:
- 35kW boiler can run at 14.5 litres per minute of hot water
- 43kW boiler can run at 17.8 litres per minute of hot water
These numbers depend on the water flow rate entering the property. We size the boiler according to the number of litres per minute of cold water the house currently has to meet demand.
Another key feature when considering a new boiler is the flue specification. How far your flue needs to go will determine which boiler you can have.
For this model, both kW outputs’ flue specifications are:
- The standard horizontal flue is 5.5m (it can be extended to 32m with an enlarged flue)
- The standard vertical flue is 8m (it can be extended to 34m with an enlarged flue)
This versatility gives us huge scope to install these boilers practically anywhere.
ecoTEC plus combi
This is our most recommended boiler at JPS Plumbing, Gas, and Electrical. It has stainless steel heat exchangers and brass hydro blocks, and we offer a 10-year warranty on this model. It is quite universal and suitable for most locations. Available in an LPG and natural gas version, it is A-rated with an 89.4% energy efficiency rating.
This boiler is available in several different outputs:
- 25kW boiler, modulating down to 4.2kW
- 32kW boiler, modulating down to 5.7kW
- 35kW boiler, modulating down to 6.4kW
- 38kW boiler, modulating down to 7.1kW
With an ‘up to one in 6’ ratio, this is slightly less than the ecoTEC exclusive with Green iQ combi, but it’s still an extremely efficient boiler.
It has built-in frost protection, making it ideal for a garage or anywhere else that can get very cold.
Again, being a combi boiler, the hot water performance is key:
- 25kW boiler can run at 10.5 litres per minute of hot water
- 32kW boiler can run at 13 litres per minute of hot water
- 35kW boiler can run at 14.3 litres per minute of hot water
- 38kW boiler can run at 15.9 litres per minute of hot water
We measure the property to work out what it needs and use those measurements to spec the right boiler to meet the property’s needs. Usually, with a combi boiler, we specify it based on the hot water because the boiler will need a lot more power for the hot water, and it will modulate itself down for the heating.
This model’s flue specifications:
- 25kW Standard horizontal flue is 12m (can be extended to 39m with an enlarged flue)
- 25kW Standard vertical flue is 16m (can be extended to 41m with an enlarged flue)
- 32kW, 35kW and 38kW Standard horizontal flue is 5.5m (can be extended to 32m with an enlarged flue)
- 32kW, 35kW and 38kW Standard vertical flue is 8m (can be extended to 34m with an enlarged flue)
Again, this versatility gives us huge scope to install these boilers practically anywhere.
ecoTEC pro combi
This model is very similar to the ecoTEC plus, with stainless steel heat exchangers and brass hydroblocks. However, it has slightly less modulation, slightly less hot water performance, and only a 7-year warranty instead of a 10-year warranty.
This boiler has three output options:
- 24kW boiler, modulating down to 5.9kW
- 28kW boiler, modulating down to 6.9kW
- 30kW boiler, modulating down to 9kW
The modulation ratio is one in four, so it is less than the ecoTEC plus.
For a 35-degree rise, the hot water performance is:
- 24kW boiler can run at 9.6 litres per minute of hot water
- 28kW boiler can run at 11.1 litres per minute of hot water
- 30kW boiler can run at 12.3 litres per minute of hot water
This model’s flue specifications (it’s the same for all the kW output models) are:
- The standard horizontal flue is 12m (it can be extended to 39m with an enlarged flue)
- The standard vertical flue is 16m (it can be extended to 41m with an enlarged flue)
We don’t generally recommend fitting this boiler model, as the ecoTEC Plus is similar but has a longer warranty, more modulation, and better hot water performance.
ecoFIT pure combi
This combi boiler is lower priced than the Ecotec Plus, which explains the lower-quality aluminium heat exchanger and plastic hydro blocks. Although it comes with a 10-year warranty, we do not recommend this boiler. Instead, we would recommend the Baxi boiler, which is of a similar spec and priced but has higher-quality stainless steel heat exchangers and brass hydro blocks.
One scenario where we would recommend the ecoFIT pure combi over the Baxi boiler is if we need a rear flue option due to space restrictions rather than having space for the flue to come out of the top.
This boiler has three output options:
- 25kW boiler, modulating down to 5.3kW
- 30kW boiler, modulating down to 6.3kW
- 35kW boiler, modulating down to 7.5kW
The modulation ratio is one in five, slightly less than the ecoTEC plus.
For a 35-degree rise, the hot water performance is:
- 25kW boiler can run at 10.4 litres per minute of hot water
- 30kW boiler can run at 12.2 litres per minute of hot water
- 35kW boiler can run at 14.1 litres per minute of hot water
This model’s flue specifications (the same for all kW output models) are:
- The standard horizontal flue is 10m (it can be extended to 25m with an enlarged flue)
- The standard vertical flue is 10m (it can be extended to 25m with an enlarged flue)
Controls for combi boilers
For Vaillant combi boilers, we usually fit the wireless VRT 350f programmable thermostat. If fitted as part of a boiler installation, it comes with a 10-year warranty.
The 350f has intelligent load compensating technology, which helps the boiler modulate to only use the energy that the property needs.
This thermostat is also Boiler Plus compliant, which is government legislation we must now adhere to.
ecoTEC exclusive with Green iQ system
Essentially, this Vaillant boiler is the system boiler version of the Green iQ combi boiler. It has a stainless steel heat exchanger and brass hydroblocks, and we can give you a 10-year warranty.
It only comes in a 27kW option, which modulates down to 4.2kW.
As there is no hot water output with a system boiler, there are no hot water performance figures.
This model’s flue specifications are:
- The standard horizontal flue is 5.5m (it can be extended to 32m with an enlarged flue)
- The standard vertical flue is 8m (it can be extended to 34m with an enlarged flue)
ecoTEC plus system
This is our most widely recommended system boiler. It has a stainless steel heat exchanger and brass hydroblocks, and we can give you a 10-year warranty.
This boiler model is available in several output options:
- 12kW boiler, modulating down to 3.3kW
- 15kW boiler, modulating down to 3.3kW
- 18kW boiler, modulating down to 4.1kW
- 24kW boiler, modulating down to 5.7kW
- 30kW boiler, modulating down to 6.4kW
- 37kW boiler, modulating down to 7.1kW
We will work out which output option you will need by sizing it to the house based on what your house needs to heat up. We estimate that as 1.5 kW per radiator plus your hot water cylinder – that will vary depending on whether you have a vented hot water cylinder or an unvented hot water cylinder.
This model’s flue specifications:
- 12kW and 15kW Standard horizontal flue is 22m (can be extended to 25m with an enlarged flue)
- 12kW and 15kW Standard vertical flue is 26m (can be extended to 27m with an enlarged flue)
- 18kW Standard horizontal flue is 12m (can be extended to 39m with an enlarged flue)
- 18kW Standard vertical flue is 16m (can be extended to 41m with an enlarged flue)
- 24kW, 30kW and 37kW Standard horizontal flue is 5.5m (can be extended to 32m with an enlarged flue)
- 24kW, 30kW and 37kW Standard vertical flue is 8m (can be extended to 34m with an enlarged flue)
ecoFIT pure system
It comes with a 10-year warranty, but we wouldn’t recommend this boiler because it has an aluminium heat exchanger and plastic hydro blocks. Instead, we would recommend the ecoTEC Plus. If we were looking for a cheaper option, we would recommend Baxi because it has a 10-year warranty and stainless steel heat exchanger and brass hydro blocks.
It comes in a range of output options:
- 12kW boiler, modulating down to 4.7kW
- 15kW boiler, modulating down to 4.7kW
- 18kW boiler, modulating down to 5.5kW
- 25kW boiler, modulating down to 6.4kW
- 30kW boiler, modulating down to 7.5kW
This model’s flue specifications (the same for all kW output models) are:
- The standard horizontal flue is 10m (it can be extended to 25m with an enlarged flue)
- The standard vertical flue is 10m (it can be extended to 25m with an enlarged flue)
Controls for system boilers
We don’t recommend a Vaillant control system for Vaillant system boilers as the wiring centres contain another PCB, which could cause problems and make your central heating system overcomplicated.
Instead, we generally fit a Drayton Digistat or a smart thermostat like a Nest or a Hive.
ecoTEC plus regular heat-only
Vaillant does not manufacture a heat-only/open vent boiler variant in the ecoTEC exclusive range. Their highest specification model for this type of boiler is the ecoTEC plus.
Even though it has a 10-year warranty, this is the only boiler where we feel that recommending the more premium ecoTEC plus boiler over the ecoFIT pure model is not justified, as the ecoFIT pure boiler is cheaper and essentially the same product.
In other types of Vaillant boiler, the ecoTEC plus range has stainless steel heat exchangers and brass hydroblocks, but the heat-only ecoTEC plus boiler has aluminium heat exchangers and plastic hydroblocks.
It comes in a range of output options:
- 12kW boiler, modulating down to 4.7kW
- 15kW boiler, modulating down to 4.7kW
- 18kW boiler, modulating down to 5.2kW
- 24kW boiler, modulating down to 6.3kW
- 30kW boiler, modulating down to 7.5kW
- 35kW boiler, modulating down to 7.5kW
This model’s flue specifications (the same for all kW output models) are:
- The standard horizontal flue is 10m (it can be extended to 25m with an enlarged flue)
- The standard vertical flue is 10m (it can be extended to 25m with an enlarged flue)
ecoFIT pure regular heat-only
We recommend this model over the ecoTEC plus boiler as it’s generally £100 cheaper than the plus model, even though it’s essentially the same because it still has an aluminium heat exchanger and plastic hydroblocks.
It comes in a range of output options:
- 12kW boiler, modulating down to 4.7kW
- 15kW boiler, modulating down to 4.7kW
- 18kW boiler, modulating down to 5.2kW
- 25kW boiler, modulating down to 6.4kW
- 30kW boiler, modulating down to 7.4kW
- 35kW boiler, modulating down to 7.5kW
This model’s flue specifications (the same for all kW output models) are:
- The standard horizontal flue is 10m (it can be extended to 25m with an enlarged flue)
- The standard vertical flue is 10m (it can be extended to 25m with an enlarged flue)
This model has a rear flue option.
As a general rule of thumb, across the whole range of heat-only boilers, we spec the Vaillant ecoFIT pure because the Baxi (Main) alternative is a completely different boiler. For heat-only boilers, we feel that Vaillant is the superior choice. However, when it comes to combi and system boilers, a Baxi boiler is often a high-quality, lower-cost alternative to a Vaillant.
Controls for heat-only/open-vent boilers
We don’t recommend a Vaillant control system for Vaillant system boilers as the wiring centres have another PCB in them, which is another thing that could go wrong and make your heating system overly complicated.
What type of Vaillant boiler do I need?
As you can see from this article, Vaillant has a wide range of gas boiler solutions. The right one for your home will depend on your priorities, available space and existing heating system.
Here are a few suggestions to help you narrow it down, but it is always best to book a visit from one of our engineers. They can assess your home, talk through your heating and hot water needs, and recommend the most suitable Vaillant boiler for your property.
- High hot water demand: Vaillant ecoTEC plus combi store – a good choice for larger homes that want combi convenience but need a stronger hot water supply.
- Most energy efficient: Vaillant ecoTEC exclusive with Green iQ – Vaillant’s premium model, designed for high efficiency, low fuel consumption and smart performance.
- Best all-rounder: Vaillant ecoTEC plus – a reliable, high-performance option for many homes, available as combi, system and heat-only models.
- Best for smaller homes: Vaillant ecoFIT pure combi – the compact size makes it a practical option for homes with limited space.
- Best for homes with multiple bathrooms: Vaillant ecoTEC plus system – works with a hot water cylinder, making it better suited to households with higher hot water use.
- Best for older heating systems: Vaillant ecoTEC plus regular – a strong option for homes already using a traditional heat-only boiler setup.
- Best for reducing heating costs: Vaillant ecoTEC exclusive with Green iQ – a strong choice if energy efficiency is your main priority, helping your home use fuel more efficiently than an older, less efficient boiler.
Ready to upgrade your heating system with a new Vaillant boiler? Get in touch
If you are a Hampshire homeowner considering a new boiler installation, speak to the knowledgeable and friendly team at JPS Plumbing, Gas and Electrical. We will be glad to offer our impartial advice, based on our years of experience in the heating industry. Along with Vaillant UK, we can recommend other market-leading brands such as Baxi UK and Glow Worm.
Contact us here, or get an instant boiler quote online now.
All technical details in this article are correct on the date of publication.
Frequently asked questions – why choose Vaillant boilers?
What is a stainless steel heat exchanger and why is it important?
The heat exchanger is one of the hardest-working parts inside your boiler. It takes the heat created by the boiler and transfers it into the water that runs through your heating and hot water system.
Some boilers use aluminium heat exchangers or more plastic internal parts. While that doesn’t necessarily make them poor quality, stainless steel is far more hard-wearing.
Many Vaillant boilers use stainless steel heat exchangers and brass hydroblocks, designed to cope with heat, pressure and regular use, day after day. As any good heating engineer will tell you, they are good-quality, durable components, meaning your boiler is more likely to work efficiently and reliably for longer.
Is the Vaillant ecoFIT Pure a good regular boiler?
Yes, the Vaillant ecoFIT Pure is a solid choice if your home already has a traditional heating system with a hot water cylinder. It is a compact, reliable regular boiler that is well suited to homes where space is limited, such as a kitchen cupboard or utility area. It is also a practical option if you are replacing an older regular boiler and want to keep your existing cylinder and pipework setup.
Can a Vaillant boiler work with smart heating controls?
Many Vaillant boilers can work with smart heating controls, giving you an easier way to manage your heating day to day. With the right setup, you can adjust the temperature from your phone, set heating schedules around your routine and avoid heating the house when nobody is home. Handy if plans change, you are running late, you’re going away, or you simply want the house warm before you walk through the door.
Why use a Vaillant Advance Installer for a new boiler?
A Vaillant Advance Installer is recognised by Vaillant for their product knowledge and installation standards. That means your new boiler is being fitted by someone who knows the Vaillant range, understands how to get the best from it, and can make sure it is set up correctly for your home.
As a Vaillant Advance Mastertech Installer, JPS Plumbing, Gas and Electrical can also offer extended warranties on selected Vaillant boilers, giving you proper support and extra peace of mind once the job is done.
What affects the installation cost of a Vaillant boiler?
The cost of installing a Vaillant boiler depends on many things, including the size of your home, your existing heating system, your chosen boiler type, hot water demand and whether any pipework or controls need updating.
A straight swap, where the new boiler goes in the same place as the old one, is usually more straightforward. If pipework needs changing, the boiler is moving location, or the system needs upgrading, the job can take more time and cost more.
The best way to get an accurate price is to book a home survey with JPS. In the meantime, you can get an idea by using our instant boiler quote tool.