Choosing a new boiler isn't something most homeowners do very often, so it's natural to want to get it right first time.
Now that WLV Plumbing & Heating are ATAG accredited installers, we're getting lots of questions about the ATAG range. What's the difference between the iC and the iC Economiser Plus? Do I need a combi, a system or a regular boiler? Which size is right for my home?
The good news is that every ATAG boiler is built to the same high standard. The right choice simply depends on your home, how much hot water you use and the heating system you've already got.
This guide explains the key differences to help you make an informed decision.
Why Choose ATAG?
ATAG are a Dutch manufacturer with a strong reputation for build quality and long warranties. Their boilers are designed and built in the Netherlands, and they're only sold through selected Gas Safe registered installers, so you know your boiler is being fitted by a team that knows it well.
Homeowners choose ATAG because of their:
- Stainless steel iCon heat exchanger, with a lifetime guarantee (subject to ATAG's terms)
- 12-year warranty as standard, with the option of up to 18 years
- Quiet running
- A-rated efficiency
- Smart control options
- Compact, wall-hung design
Whether you live in a flat in Wolverhampton or a family home in Dudley, Walsall or Birmingham, there's an ATAG boiler to suit your home.
ATAG iC Economiser Plus
ATAG's Most Efficient Combi Boiler

The iC Economiser Plus is ATAG's flagship combi boiler. Its patented Economiser captures heat from the flue gases that would normally go to waste and uses it to pre-warm the cold water coming into the boiler, so you get your hot water using less gas.
It's also Quiet Mark approved, which makes it a great choice if your boiler lives in the kitchen or near a bedroom.
It comes in three sizes (27kW, 35kW and 39kW), with hot water flow rates from 12.6 to 17 litres per minute.
It's ideal for
- Family homes
- Homes with one or two bathrooms
- Busy households that use a lot of hot water
- Boilers fitted in a kitchen or near a bedroom
Benefits
- Economiser for lower hot water running costs
- Strong hot water flow rates
- Quiet Mark approved
- No hot water tank needed
- 12-year warranty as standard, up to 18 years
If you want the most efficient ATAG combi and you're planning to stay in your home for years, the Economiser Plus is well worth considering.
ATAG iC Combi
ATAG Quality in a Compact Package

The iC combi gives you ATAG's build quality and stainless steel heat exchanger, without the Economiser. It heats your water on demand, so there's no need for a hot water tank, which frees up valuable cupboard space.
It comes in four sizes (24kW, 28kW, 36kW and 40kW), with hot water flow rates from around 10 to 16 litres per minute.
It's best suited to
- Flats and smaller homes (24kW and 28kW)
- One bathroom properties
- Larger homes with more hot water demand (36kW and 40kW)
- Homeowners who want ATAG quality at a lower price than the Economiser Plus
Benefits
- The same stainless steel iCon heat exchanger
- Hot water on demand
- No hot water tank needed
- Quiet running
- 12-year warranty as standard, up to 18 years
If you're replacing a combi in a smaller home, the iC often represents excellent value for money.
ATAG iS System Boiler
Plenty of Hot Water for Busier Homes

A system boiler works with a hot water cylinder, so you can run a shower and a tap at the same time without losing pressure. The pump and expansion vessel are built into the boiler, which keeps the installation neat and tidy.
It comes in five sizes: 15kW, 18kW, 24kW, 32kW and 40kW.
It's ideal for
- Homes with two or more bathrooms
- Larger families
- Homes that already have a hot water cylinder
- Anywhere with high hot water demand
Benefits
- Run more than one tap or shower at once
- Pump and expansion vessel built in
- No cold water tank needed in the loft
- A wide choice of sizes
- 12-year warranty as standard, up to 18 years
If your household regularly needs hot water in more than one room at a time, the iS is often the better choice over a combi.
ATAG iR Regular Boiler
The Easy Upgrade for Traditional Systems

If your home has a cold water tank in the loft and a hot water cylinder, a regular (heat only) boiler is often the simplest upgrade. The iR lets you move to a modern, efficient ATAG boiler without changing your whole heating system.
It comes in five sizes: 15kW, 18kW, 24kW, 32kW and 40kW.
It's particularly suited to
- Older properties
- Larger homes with an existing regular system
- Homes with low mains water pressure
- Homeowners who want to keep disruption to a minimum
Benefits
- A straightforward replacement for older systems
- Less upheaval than changing system type
- A wide choice of sizes
- 12-year warranty as standard, up to 18 years
If your current system works well and you simply need a new boiler, the iR is usually the most sensible route.
Which ATAG Boiler Is Best?
The answer depends entirely on your home.
Here's a simple comparison.
| Feature | iC Economiser Plus | iC Combi | iS System | iR Regular |
|---|---|---|---|---|
| Boiler Type | Combi | Combi | System | Regular (heat only) |
| Sizes | 27, 35 and 39kW | 24, 28, 36 and 40kW | 15, 18, 24, 32 and 40kW | 15, 18, 24, 32 and 40kW |
| Hot Water | On demand, 12.6 to 17 litres per minute | On demand, around 10 to 16 litres per minute | Stored in a cylinder | Stored in a cylinder |
| Hot Water Cylinder | Not needed | Not needed | Needed | Needed |
| Loft Tank | Not needed | Not needed | Not needed | Needed |
| Quiet Mark | Yes | No | No | No |
| Best For | Family homes wanting top efficiency | Flats and smaller homes | Homes with two or more bathrooms | Older homes with a traditional system |
| Warranty | 12 years, up to 18 | 12 years, up to 18 | 12 years, up to 18 | 12 years, up to 18 |
Which Boiler Would We Recommend?
Every installation starts with understanding your home rather than recommending a particular boiler.
At WLV Plumbing & Heating, we consider:
- The size of your property
- Number of radiators
- Number of bathrooms
- Hot water demand
- Your mains water pressure
- Existing heating system
- Your budget
- Future plans
Sometimes the most expensive boiler isn't the right choice. Likewise, choosing the cheapest option isn't always the most cost-effective in the long term.
Our aim is to recommend the ATAG boiler that's best suited to your property and lifestyle.
Getting the Most From Your ATAG Warranty
Every ATAG boiler comes with a 12-year manufacturer's warranty as standard. When it's fitted with ATAG's full control pack, that can go up to 18 years, one of the longest boiler warranties in the UK.
To keep your warranty valid, ATAG ask for your boiler to be registered within 30 days of installation and serviced every year. As ATAG accredited installers, we register your boiler for you, and our WLV Comfort Club makes the yearly service easy, with your annual service included in a simple monthly plan.
Join the WLV Comfort ClubCommon Questions
Is the ATAG iC Economiser Plus worth the extra money?
If your home uses a lot of hot water, or you're planning to stay for many years, the Economiser's savings on hot water and its stronger flow rates can make it worth the extra. For a smaller home with lighter hot water use, the standard iC is often the better value.
What's the difference between the ATAG iC and the iC Economiser Plus?
Both are combi boilers with ATAG's stainless steel heat exchanger. The Economiser Plus adds the patented Economiser, which recovers heat from the flue gases to pre-warm the incoming water, and it's Quiet Mark approved.
Which ATAG boiler is best for a three-bedroom house?
Many three-bedroom homes with one bathroom suit a 27kW iC Economiser Plus or a 28kW iC combi. If you've got two bathrooms or more, a larger combi or an iS system boiler may suit you better.
A professional survey will make sure the correct boiler is recommended.
Are ATAG boilers reliable?
ATAG are known for their build quality, and they back it up with a lifetime guarantee on the heat exchanger and a warranty of up to 18 years.
Can you help me choose the right ATAG boiler?
Absolutely. Every home is different, and we believe the best boiler is the one that's correctly sized for your property and heating requirements.
We'll explain your options in plain English and recommend a solution that offers the best balance of performance, efficiency and value.
Why Choose WLV Plumbing & Heating?
As ATAG accredited installers, we don't believe in recommending a boiler simply because it's the most expensive.
Instead, we take the time to understand your home, your heating system and your future plans before recommending the most suitable ATAG boiler.
Our experienced engineers install boilers throughout Wolverhampton, Dudley, Walsall and Birmingham, providing honest advice, careful workmanship and a fixed-price quote following a boiler survey.

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Need Help Choosing an ATAG Boiler?
If you're unsure which ATAG boiler is right for your home, our friendly team is here to help. We'll look at your property, talk through your options and give you a fixed-price quote following a boiler survey.
Call: 01902 283124 | WhatsApp: 07415 974160





