The Vaillant ecoTEC Pro range is three gas combi boilers, the Pro 24, 28 and 30, built for flats and small to medium homes with one bathroom. All three share the same compact casing, controls and features. The only real difference is how much hot water they can deliver. If you’re ready to upgrade, see how we supply and fit the range on our Vaillant boiler installation page.
The whole range is still current in 2026. This guide compares each model side by side, explains which size suits which home, and shows where the higher-spec ecoTEC plus becomes the better choice. For our take on Vaillant as a brand, including reliability and how it compares with other manufacturers, read our full Vaillant boilers review.
How Do The ecoTEC Pro 24, 28 And 30 Compare?
All three give roughly 25kW for heating; hot water flow rises from 9.6 to 12.3 litres per minute as you go up the range.
| Model | Heating output | Hot water output | Hot water flow (35°C rise) | Fuel | Best for |
| ecoTEC Pro 24 | 5.9 to 24.8kW | 23.4kW | 9.6 litres per minute | Natural gas | Flats and 1 to 2-bed homes |
| ecoTEC Pro 28 | 5.9 to 25.9kW | 27.2kW | 11.1 litres per minute | Natural gas | 2 to 3-bed homes, one bathroom |
| ecoTEC Pro 28 LPG | Up to 25.3kW | 27.2kW | 11.1 litres per minute | LPG | Off-grid 2 to 3-bed homes |
| ecoTEC Pro 30 | Up to 25.7kW | Up to 30kW | 12.3 litres per minute | Natural gas | Busier 3-bed homes, one bathroom |
Every model is ErP A-rated for heating and hot water and measures 720 x 440 x 338mm (H x W x D). All are current models in 2026.
What Is The Vaillant ecoTEC Pro Range?
It’s Vaillant’s mainstream combi range, aimed at small to medium homes.
It sits below the ecoTEC plus, which Vaillant remastered in 2023, and the premium ecoTEC exclusive. Vaillant pitches the Pro at smaller homes, and in our experience that’s exactly where it works best.
Every Pro model is a combi boiler. It heats water straight from the mains when you open a tap, so there’s no hot water cylinder and no cold water tank in the loft. That makes the range a natural fit for flats, terraces and semis where space is tight. If you’re not sure a combi is right for you, our guide to combi, system and conventional boilers explains the differences.
What Features Do All ecoTEC Pro Boilers Share?
They all share the same compact casing, modulating burner, hot water pre-heat, display, smart control options and frost protection, because they’re built on one platform.
- Compact casing: 720mm high, matching a standard kitchen wall unit, so it usually fits inside a cupboard.
- Modulating burner: output adjusts to demand, giving steadier running and less wasted gas in mild weather.
- Hot water pre-heat: a warm start function shortens the wait for hot water, and you can switch it off.
- Digital display: shows pressure, temperatures and fault codes. Our Vaillant error codes guide explains what they mean.
- Smart control options: works with Vaillant’s sensoHOME and sensoCOMFORT controls and the myVAILLANT app, as well as standard programmers and thermostats.
- Frost protection: the boiler fires automatically to protect itself in freezing conditions.
The Pro 28 and Pro 30 also carry Quiet Mark accreditation.
Which ecoTEC Pro Size Is Right For Your Home?
Pick by hot water demand, not house size, because heating output barely changes between the three models.
All three can deliver roughly 25kW to the radiators. That’s enough for most of the homes this range is aimed at. What changes is hot water, so the choice comes down to how many people use it at once and how strong your mains supply is.
Which Model Suits A Flat Or Small Home?
The Pro 24. At 9.6 litres per minute it runs one shower or one bath tap well.
It’s a good match for flats and one or two-bedroom houses with a single bathroom and up to around 10 radiators. Read our full Vaillant ecoTEC Pro 24 review.
Which Model Suits Most Two And Three-Bed Homes?
The Pro 28, which gives 11.1 litres per minute. That’s enough for a decent mixer shower with some margin when another tap opens.
It suits most two and three-bedroom homes with one bathroom and up to around 12 to 14 radiators. It’s also the only Pro model available in an LPG version. Read our Vaillant ecoTEC Pro 28 review.
Which Model Suits A Busier Single-Bathroom Home?
The Pro 30, which pushes hot water flow to 12.3 litres per minute.
It suits three-bedroom family homes where the shower and kitchen tap often run together. It also works with a small en-suite used at different times from the main bathroom. It only makes sense if your mains supply can keep up. Read our Vaillant ecoTEC Pro 30 review.
When Should You Look Beyond The Pro Range?
When you have two bathrooms that are often in use at the same time. None of the Pro models is the right fit there.
Look at a larger ecoTEC plus combi or a system boiler with a cylinder instead. Our guide on how to size a combi boiler walks through the calculation.
How Does The ecoTEC Pro Compare With The ecoTEC Plus And Sustain?
The Pro suits single-bathroom homes, the plus gives more hot water and wider modulation, and the sustain targets refurbishment and new-build work.
Vaillant sells three combi ranges that overlap in size, which can be confusing.
| Range | Combi outputs | Hot water flow (35°C rise) | Who it suits |
| ecoTEC Pro | 24, 28, 30kW | 9.6 to 12.3 litres per minute | Small to medium homes with one bathroom |
| ecoTEC plus (remastered 2023) | 26, 32, 36, 40kW | 10.6 to 16.3 litres per minute (940 model higher) | Medium to larger homes wanting wider modulation and more hot water |
| ecoTEC sustain | 24, 28, 34kW | 9.9 to 14.1 litres per minute | Refurbishment and new-build work, including rental homes |
The ecoTEC plus has a stainless steel heat exchanger and a much lower minimum output, down to 2.5kW on the 826. It runs more smoothly when demand is low, but it costs more. Our Vaillant 32kW combi review covers the ecoTEC plus 832 in detail.
The ecoTEC sustain shares the Pro’s footprint and flue position, so it can replace an ecoTEC Pro with minimal changes. For most homeowners, though, the choice is between the Pro and the plus.
How Much Does An ecoTEC Pro Cost To Install In 2026?
A like-for-like combi swap typically costs £1,900 to £2,900 fitted, depending on the model, or £2,300 to £3,200 for the LPG version.
These guide ranges assume a straightforward swap in the same position, including a standard flue, magnetic filter, chemical flush and basic controls.
| Model | Guide installed price (like-for-like swap) |
| ecoTEC Pro 24 | £1,900 to £2,600 |
| ecoTEC Pro 28 | £2,000 to £2,800 |
| ecoTEC Pro 28 LPG | £2,300 to £3,200 |
| ecoTEC Pro 30 | £2,100 to £2,900 |
These are guide figures and prices vary by job. Moving the boiler, a new flue route or converting from a system or regular boiler typically adds several hundred pounds or more.
See how much a new boiler costs for a full breakdown, and boilers on finance for monthly payment options.
What Are The Pros And Cons Of The ecoTEC Pro Range?
The main pros are one compact casing across all sizes and A ratings throughout. The main con is that no Pro model suits two busy bathrooms.
Pros
- One compact casing across all three sizes
- A-rated for heating and hot water
- Simple to use and familiar to engineers
- Smart control options through Vaillant’s own controls and app
- LPG option in the 28kW size
Cons
- Not suited to homes with two busy bathrooms
- Higher minimum output than the ecoTEC plus
- Only one LPG model
- Bigger badge numbers add hot water, not heating power
Is The Vaillant ecoTEC Pro Range Worth It?
Yes, for a small to medium home with one bathroom.
It’s a compact, A-rated combi that engineers know well, and the three sizes cover most flats, terraces and semis. Choose by hot water demand rather than house size alone. Check your mains supply first, too.
Choose It If
- You have one bathroom and a flat, terrace or semi
- You want a compact combi that fits in a kitchen cupboard
- You want a well-known brand at a mid-range price
Look Elsewhere If
- You have two bathrooms in regular use at the same time
- You want the widest modulation range and a higher spec
- You need an LPG boiler larger than 28kW
Get A Free Boiler Quote From Clever Energy Boilers
Clever Energy Boilers carries out new boiler installations for homeowners and landlords across the North West, Yorkshire and the Midlands. Our experienced, professional and registered installers will check your mains supply and hot water use first. Then we’ll recommend the right ecoTEC Pro, or tell you if a different boiler would suit you better.
Long, market-leading warranties are on offer through Clever Energy for the boilers we install. You can also add a servicing plan so the yearly service is one less thing to remember.
Get your free, no-obligation boiler quote online in a few minutes.
Frequently Asked Questions
How Many Boilers Are In The Vaillant ecoTEC Pro Range?
Three outputs: the ecoTEC Pro 24, 28 and 30. The 28 also comes in an LPG version, so there are four variants in total.
Is The Vaillant ecoTEC Pro Range Discontinued?
No. The ecoTEC Pro 24, 28 and 30 are all current models in 2026. It was the older ecoTEC plus range that Vaillant replaced in 2023.
Which ecoTEC Pro Is Best For A Three-Bedroom House?
The ecoTEC Pro 28 suits most three-bedroom homes with one bathroom. Go for the Pro 30 if several people use hot water at once and your mains supply is strong.
Do Bigger ecoTEC Pro Models Heat The House Faster?
Not really. All three models deliver around 25kW to the radiators. The higher numbers mainly mean more hot water at the tap.
What Is The Difference Between The ecoTEC Pro And ecoTEC Plus?
The ecoTEC plus has a stainless steel heat exchanger, a much wider modulation range and higher flow rates in its larger sizes. The ecoTEC Pro is simpler and cheaper, and suits smaller single-bathroom homes.