Is the Vaillant ecoFIT pure a good boiler?
For most ordinary UK homes, yes. Vaillant rates the whole ecoFIT pure range at 94% ErP efficiency and ErP A for both heating and hot water, it is hand-built in Vaillant's Derbyshire plant, and the combi and system models share the same compact 700 x 390 x 295 mm case that will go inside a kitchen cupboard. It is the sensible, no-frills Vaillant rather than the flagship.
Three honest weak points:
- The guarantee is only two years out of the box. The seven and ten year figures you see advertised are conditional and depend on who fits it. See the guarantee section below.
- Not every model is Quiet Mark certified. Vaillant's own footnote on the combi range says the certification excludes the 25kW and 35kW models, and on the system range it excludes the 15kW, 18kW and 30kW models. If quietness is why you are buying it, check the exact model number.
- vSMART, the smart control this boiler was launched with, is now marked discontinued on Vaillant's own product listing. The range still works with Vaillant's current controls, but do not buy on the strength of an old vSMART review.
This review uses Vaillant's own published figures. If you have decided you want a new boiler, or you need the one you have repaired, tell us what is happening and we will call you back.
What size ecoFIT pure do I need?
Sizing is a job for your installer, working from a room-by-room heat loss calculation and your actual mains flow rate, not a rule of thumb on a web page. Below are Vaillant's own published figures, so you can sanity-check the model on your quote.
ecoFIT pure combi (models 825, 830, 835)
Combi boilers heat hot water on demand, so there is no cylinder and no loft tank. The trade-off is that the flow rate caps how many taps and showers you can run at once. Vaillant publishes these figures:
| Model | Signature output | Hot water flow rate (at Δ35K) | Modulation | Dry weight |
|---|---|---|---|---|
| ecoFIT pure 825 | 25 kW | 10.4 l/min | 1:5 | 32 kg |
| ecoFIT pure 830 | 30 kW | 12.2 l/min | 1:4.9 | 33 kg |
| ecoFIT pure 835 | 35 kW | 14.1 l/min | 1:4.9 | 33 kg |
Two things about those flow rates. They are measured at a 35 degree temperature rise. And no combi can push hot water out faster than your mains brings cold water in, so if your incoming mains is weak, a bigger boiler will not fix your shower.
ecoFIT pure system (models 612, 615, 618, 625, 630)
The system version works with a separate hot water cylinder, which is what you want if two showers regularly run at the same time. Vaillant lists five outputs, 12, 15, 18, 25 and 30kW, with dry weights of 31 to 32 kg and the same 700 x 390 x 295 mm case.
ecoFIT pure open vent
There is also an open vent (regular) version in 12, 15, 18, 25, 30 and 35kW, at only 22 kg dry. This is the one for a traditional system that keeps a feed and expansion tank in the loft as well as a cylinder.
If you are not sure which of the three types your home has, our guide to combi versus system boilers walks through the difference and what swapping type actually involves.
How efficient is the ecoFIT pure?
Vaillant publishes 94% ErP efficiency across the combi, system and open vent ranges, and describes the range as ErP A rated for both hot water and heating efficiency. That is current-generation performance, level with the mainstream competition.
The figure most people miss is the modulation. Vaillant quotes modulation ratios of roughly 1:5 on the popular models and says the boiler will reduce itself to just 20% of its maximum output when you do not need as much heat. In a small house that matters more than the headline percentage: a boiler that cannot turn down far enough spends the winter switching on and off.
One caveat applies to any A-rated condensing boiler. The rating comes from a standard test. In your house it only gets close if the water returning from the radiators is cool enough for the boiler to condense, which comes down to how your installer sets the flow temperature and balances the system. Ask about that when you get the quote.
How long is the Vaillant ecoFIT pure guarantee?
Two years as standard. Vaillant's own published guarantee table then shows two conditional upgrades for this range:
| Situation | Guarantee |
|---|---|
| Standard, out of the box | 2 years |
| Registered by a myREWARDS installer | 7 years |
| Registered by a myREWARDS installer and fitted with a Vaillant filter | 10 years |
Read that table before you sign a quote, because the long guarantee is not something you can add later on your own. Vaillant states that registration must be done within 30 days of installing the appliance, and that the homeowner must arrange an annual service to keep it valid. So ask your installer: are you a myREWARDS member, are you fitting a Vaillant filter, and will you register it for me?
If the boiler is already in and you are not sure what you ended up with, our guide on how to check a Vaillant boiler warranty shows you where to look and what to quote when you ring.
You can register a guarantee directly with Vaillant.
Register your Vaillant guarantee
What does a Vaillant ecoFIT pure cost?
Vaillant does not publish a homeowner price for the ecoFIT pure, and we are not going to invent one. What we can tell you is what moves the number on a real quote.
- The flue route. Vaillant quotes maximum flue lengths of 10 m on 60/100 and 25 m on 80/125, with top and rear options. A short rear flue against an outside wall is the cheap case. Long runs are not.
- Whether the boiler moves. Fitting in the same spot is a different job from relocating it to a cupboard upstairs.
- The state of the existing system. A chemical flush, a filter and a gas pipe upgrade are common line items, and they are real work rather than padding.
- The guarantee package. A Vaillant filter is what takes you from 7 years to 10, so price that line separately and decide with your eyes open.
Ask for an itemised quote that separates boiler, flue, parts and labour, and that says in writing who registers the guarantee.
What goes wrong with a Vaillant ecoFIT pure?
Vaillant boilers display a fault code on the front panel, so you can tell an engineer what is wrong before anybody gets in a van. These are the three codes homeowners meet most often, described using Vaillant's own published fault code list.
F.22, low water pressure
Vaillant gives the cause as water pressure below the normal 1 to 1.5 bar range, and also lists a faulty pressure sensor, a faulty internal expansion vessel and loose wiring. Topping up through the filling loop is a homeowner job, and your user manual shows you where the loop is. If the pressure drops again within days, book an engineer, because something is leaking. Our full guide to the Vaillant F.22 fault code covers it step by step.
F.28, no flame detected at ignition
Vaillant lists not enough gas reaching the boiler, condensate backed up from a blocked condensate pipe, a faulty ignition electrode, a faulty circuit board, or a flue problem. The safe checks you can do yourself are the ones Vaillant names: see whether your other gas appliances work, check a prepayment meter has credit, and in cold weather check for ice in an outdoor condensate pipe. Beyond that it is a job for an engineer, and opening the boiler casing is dangerous. See our Vaillant F.28 guide.
F.75, pump and pressure fault
Vaillant lists system pressure below the normal 1 to 1.5 bar range, air in the system, a defective water pressure sensor, a defective internal pump, or an open circuit in the cable harness. The pressure you can check yourself. The pump and the sensor you cannot.
Safety, plainly. Anyone working on gas appliances in a home must be Gas Safe registered and competent in that area of gas work, and HSE states it is illegal for anyone else to do it. Never let an unregistered person open your boiler, and ask to see the engineer's Gas Safe ID card. HSE also advises an annual service by a Gas Safe registered engineer, which is the same annual service Vaillant requires to keep your guarantee valid. If you smell gas or suspect carbon monoxide, leave the appliance alone, ventilate the property and call the free National Gas Emergency Service on 0800 111 999 straight away.
Not sure what your boiler is telling you?
Tell us the fault code and what the boiler is doing. We will call you back and, if it needs an engineer, talk you through the options and what it costs.
If your ecoFIT pure is out of guarantee
Once the manufacturer's guarantee runs out, repairs are on you. A Smart Plan boiler and central heating cover plan is one way to spread that cost: you pick only the cover you want, parts and labour are included up to the cover limit, and repairs go to a national network of thousands of Gas Safe registered engineers. Be clear on the terms. A £95 call-out fee applies in the first 30 days and in certain other situations, call-out hours are Monday to Friday, 08:00 to 18:00, and we aim to get an engineer out to you within two working days. Boiler cover is limited to £500 per 12-month period if the boiler is under seven years old, or £200 if it is over seven. Once you use a service, a 12-month agreement period applies. It is a service plan, not insurance.
Vaillant ecoFIT pure specifications
Every figure below is Vaillant's own published technical data for the range.
| Case dimensions (H x W x D) | 700 x 390 x 295 mm (combi and system) |
| Dry weight | 32 to 33 kg (combi), 31 to 32 kg (system), 22 kg (open vent) |
| Fuel type | Gas |
| ErP efficiency | 94% |
| ErP energy rating | A for heating and A for hot water |
| Heat exchanger | Aluminium |
| NOx class | 5 |
| Sound power (ErP) | 49 to 52 dBa (combi 25 to 35kW), 45 to 54 dBa (system 12 to 30kW) |
| Maximum flue length | 10 m (60/100), 25 m (80/125) |
| Rear flue option | Yes, all models |
| Standard guarantee | 2 years, up to 10 years conditionally |
| Built | Derbyshire, UK |
Full data sheets and manuals sit on Vaillant's own ecoFIT pure page, and the complete code list is on Vaillant's boiler fault codes page.
More on the ecoFIT pure
Is the ecoFIT pure better than the ecoTEC plus?
On Vaillant's published guarantee table the ecoTEC plus carries a 5-year standard guarantee against the ecoFIT pure's 2 years, and both can reach 10 years when registered by a myREWARDS installer with a Vaillant filter. If the out-of-the-box guarantee matters to you, that is the gap to weigh against the price difference on your quote.
How long should an ecoFIT pure last?
Nobody can honestly give you a number: it depends on water quality, how well the system was flushed at install, and whether it gets serviced. The annual service is not optional if you want the long guarantee. Vaillant requires the homeowner to arrange one, and HSE advises an annual service on safety grounds anyway.
