Vaillant ecoTEC plus: specifications and warranty

The Vaillant ecoTEC plus is the company's flagship UK gas boiler line, sold as a combi in 25kW, 32kW, 35kW and 38kW outputs and as a system boiler in 12kW, 15kW, 18kW, 24kW, 30kW and 37kW outputs¹. Every Vaillant boiler is ErP A rated, which the maker equates to an energy efficiency of 90%⁴. The ecoTEC plus open vent boiler carries a 5-year out-of-the-box guarantee, and the guarantee can be extended up to 10 years when the boiler is fitted by a myREWARDS installer¹.

For a household, the appeal is a well-supported appliance with a long guarantee and a UK build: the ecoTEC plus is hand-built at Vaillant's plant in Belper, Derbyshire⁵. The dependence is equally clear. The boiler runs on gas from the grid and a gas supplier, needs electricity for ignition, controls and pumping, and the longest guarantee depends on who fits it and on a protection kit being registered¹.

The ecoTEC plus range: combi, system and open vent models

The line splits by system type rather than by badge. The combi range covers 25kW, 32kW, 35kW and 38kW outputs, which spans a small flat through to a larger house with more than one bathroom³. The system range runs from 12kW to 37kW across six outputs, and Vaillant describes it as available in a range of outputs to support almost any requirement¹. The open vent boiler is the third variant in the family¹.

Output choice is a sizing question, not a quality one. A combi at the lower end of the range suits a property with one bathroom and moderate hot water demand, while the larger outputs exist for simultaneous demand. The system boiler works with a separate cylinder, so the cylinder and its recovery time matter as much as the boiler output. The general principles are set out in boiler sizing and the differences between the two system types in combi boilers and system boilers.

The ecoTEC plus sits above the ecoTEC pro in the Vaillant hierarchy. The pro range is engineered in Germany and manufactured in the UK, and carries a 7-year free extended guarantee when registered through Vaillant Advance⁶. The ecoTEC exclusive sits above the plus, with combi models at 35kW and 43kW and a single 27kW system boiler, using Extra-Condense technology and carrying Vaillant's Green iQ mark⁸.

Specifications and efficiency: ErP A rated, with Quiet Mark certification

Vaillant states that all its boilers are ErP A rated, meaning they have an energy efficiency of 90%⁴. That is a band rating rather than a model-level test figure, and it applies across the gas boiler range rather than to the ecoTEC plus alone. The ecoTEC Plus Combi Boiler 2023 holds Quiet Mark certification, and the ecoTEC plus system boiler range is listed on Quiet Mark's product pages². Quiet Mark certification is a noise rating, not an efficiency one, and it matters most where a boiler is sited near a bedroom or living space.

The ecoTEC plus system range is described as compatible with Vaillant's complete range of intelligent controls including vSMART, and the 2023 combi works alongside the myVAILLANT connect internet gateway². The 2023 combi is also described as offering enhanced performance specifically for the UK market⁹.

What determines real-world efficiency is whether the boiler condenses, which depends on return water temperature rather than the badge. The controls and flow temperature settings that govern this are covered in heating controls and thermostats and boiler flow temperature.

Warranty: 5 years standard, 10 through a myREWARDS installer

The ecoTEC plus open vent boiler gets a 5-year out-of-the-box guarantee, and the ecoTEC plus guarantee can be extended up to 10 years when the boiler is fitted by a myREWARDS installer¹. The ecoTEC plus combi range carries an option to purchase an extended warranty up to 10 years when registered by an Advance installer³. Vaillant's wider guidance states that guarantees of up to 10 years are available on gas boilers through a Vaillant Advance installer⁵.

The 10-year term is conditional rather than automatic. Vaillant states that a 10-year guarantee is available when the boiler is installed and registered with a Boiler Protection Kit by a Vaillant Advance installer⁵. The ecoTEC exclusive terms make the same point in a different form: eligibility applies when registered with either the Boiler Protection Kit or the Advanced Boiler Protection Kit, which includes a filter⁸.

Registration runs through the myVAILLANT Web online portal, or the installer can register on the householder's behalf and offer an extended guarantee period¹⁰. The benchmark Commissioning record from the back of the product manual is the document the registration relies on¹¹. Vaillant's guarantee covers repair of any defects related to the manufacturer of the appliance¹⁰. The wider conditions and the registration process are set out in boiler warranties.

What the warranty covers, and what can void it

Vaillant's guarantee covers the repair of any defects related to the manufacturer of the appliance, with a call-out by a service engineer covering both parts and labour¹⁰. That is a defects guarantee, not a maintenance contract, and it does not cover wear and tear.

The exclusions published for Vaillant's heat pump guarantee give the clearest picture of the maker's standard position: the guarantee does not include cover for wear and tear, willful damage, abnormal storage or working conditions, accidental damage, negligence, damage by animals, rodents, birds, pests or external factors, and failure to operate per instructions¹². The cylinder guarantee terms exclude damage due to frost, transient voltages, or lightning strikes¹¹.

Servicing is the other condition. Vaillant's heat pump guarantee states that if the heat pump has not been serviced annually, the heat pump guarantee will become invalid¹². The aroSTOR cylinder guidance asks householders to book an annual service¹³. For the ecoTEC plus boiler itself, the published terms do not set out a missed-service clause in the same words, so the position on a skipped service is less explicit for this range than for the heat pump line. The servicing regime generally is covered in boiler servicing and maintenance.

Cost: what the figures do and do not show

There is no published Vaillant list price for an ecoTEC plus, and no supplied-and-fitted figure for this model in the material available. Prices are installer-quoted after a survey of the property and the existing system.

The figures that do exist are for boiler types rather than this model. Vaillant's own guidance puts a system boiler at £500 to £2,000 depending on the model, size and manufacturer¹⁴. Independent statistics give a heat-only oil boiler at £1,200 to £2,450 with an average total cost of £3,075, and a system oil boiler at £1,450 to £2,375 with an average total cost of £3,163¹⁵. A wall-mounted electric boiler with cylinder is listed at £1,750 to £2,000, an average of £1,875¹⁵. Electric boiler installation is put at £3,000 to £6,000¹⁶, and biomass boiler equipment at £5,000 to £10,000 before installation¹⁷. Checkatrade figures cited in independent guidance put a new boiler at around £1,500¹⁷.

Those are different fuels and different technologies, so they frame a quote rather than predict one. Three things move an ecoTEC plus quote: the output and variant chosen, whether the system type is changing, and flue or siting work. VAT treatment is not stated in any of the figures above, so they should be read as quoted rather than as confirmed VAT-inclusive prices. Wider cost context is in new boiler cost.

Smart controls and compatibility

Vaillant's own controls are the sensoCOMFORT, sensoHOME, sensoROOM and sensoROOM pure, and myVAILLANT connect pairs with that range¹⁸. The sensoCOMFORT and sensoHOME are programmable room thermostats providing both time and temperature control in one device¹⁸. The sensoCOMFORT works with all Vaillant heating appliances including boilers and heat pumps, and is compatible with myVAILLANT connect and the myVaillant app for a fully integrated smart home heating system¹⁹. Vaillant describes the sensoCOMFORT, sensoHOME and sensoROOM as the best way to make the most of a Vaillant boiler²⁰.

Room-by-room control is achieved by pairing smart controls such as the sensoCOMFORT with thermostatic radiator valves²¹. The ecoTEC plus system range is compatible with Vaillant's complete range of intelligent controls including vSMART, and the 2023 combi works alongside the myVAILLANT connect internet gateway².

This is where the range creates its clearest dependence. Local control at the boiler and at a wired programmer continues without an internet connection, but scheduling from away, energy monitoring and remote diagnostics depend on a home broadband connection, Vaillant's servers and a manufacturer's app. Third-party thermostat compatibility is not stated in the manufacturer's material. For comparison, Hive is described as compatible with other smart devices across the home such as Amazon Alexa, Google Assistant and Philips Hue²². The wider picture is in heating controls and thermostats.

Reliability and reputation: five stars from engineers

Vaillant reports achieving 5 stars in reliability and 5 stars in engineer recommendations for gas boilers, and states it has been named Which? Recommended Brand for Gas Boilers¹. The ecoTEC plus system range is described as coming from proven German engineering combined with award winning UK manufacturing²³.

These are favourable indicators rather than a guarantee of individual performance, and they are survey-based: engineer approval measures what fitters see across many installations, not the odds for one house. Installation quality, system cleanliness and annual servicing shape lifespan more than the badge does. No expected service life figure is published for the ecoTEC plus. For context on how long boilers last generally, see how long do boilers last. A side-by-side comparison with the main rival brand is at Worcester Bosch vs Vaillant.

Made in Derbyshire: the company behind the boiler

The ecoTEC plus is hand-built at Vaillant's manufacturing plant in Belper, Derbyshire, using premium quality components and materials⁵. Vaillant Group UK manufactures high-efficiency boilers and heat pumps at Belper, and runs a facility in Derby that produces hot water cylinders²⁴. More than 700 colleagues are based across the Derbyshire sites²⁴. The ecoTEC pro is also hand-built at the Derbyshire plant, and the ecoFIT pure likewise⁶. Vaillant Group UK Limited is registered at Nottingham Road, Belper, Derbyshire, DE56 1JT¹¹.

UK assembly shortens the supply chain for parts and service, though the products are engineered in Germany². The company also reports 45,000+ installers registered through myREWARDS, which is the network that carries the extended guarantee terms²⁴.

On hydrogen, the ecoTEC Plus Combi Boiler 2023 is described as suitable to work safely and efficiently with up to a 20% hydrogen mix⁹. That is tolerance of a blend in the existing gas network, not a boiler that burns pure hydrogen, and no domestic hydrogen supply exists to feed one. The claim is examined in hydrogen-ready boilers.

Where the ecoTEC plus fits a household's independence

A Vaillant ecoTEC plus keeps a home on the gas grid and on a gas supplier, with an electrical dependence for ignition, controls and pumping. Remote features add a dependence on broadband and the manufacturer's app, and the longest guarantee depends on a continuing relationship with a registered installer. Vaillant states that the ecoTEC plus system boiler is extendable with renewables systems such as solar panels and heat pumps¹⁴, which describes a system that can be added to rather than a boiler that generates its own energy.

The alternatives that change the fuel rather than the appliance are covered in heat pumps compared with boilers, solar thermal water heating and heating and energy independence. For the brand's full UK range, see Vaillant boilers.