COMBI BOILER REVIEWS: CHOOSING THE BEST BOILER FOR YOUR HOME

A combi boiler replacement is a big expense for any household. For a boiler installation that will last for decades, it’s important to get as much information as possible before deciding on the best brand for you. You want your new boiler to be reliable, efficient, and long-lasting.

Factors to Consider When Buying a Combi Boiler

There are a number of factors to consider when buying a combi boiler. Price might be your first consideration. As with other consumer purchases, compromising on quality to reduce the initial cost may mean paying a price later in repairs and inconvenience. Cheap boilers are often difficult to repair and hard to find parts for, which means heating engineers may be reluctant to work on them.

Long-Term Peace of Mind
Long-term peace of mind is important to most boiler buyers. Some boilers offer up to 14 years of parts and labour warranty, meaning that if the boiler goes wrong, the manufacturer will fix it for free.

Minimum Heating Output
Another factor to consider is the minimum heating output. This means that the boiler can be adjusted to match the size of the heating system in your house. A combi boiler with a hot water output of 30 kW doesn’t need to work hard to heat your radiators. By lowering the heating output to match the size of your system, you will be wasting less energy. If your boiler’s minimum heating output can only be lowered to 10 kW, you’ll probably be burning more gas than necessary. The lower this number is, the more efficient your boiler.

What size boiler do I need? (theheatinghub.co.uk)

Hot Water Flow Rate
We also mention hot water flow rate, which is important when choosing your new combi boiler. Generally speaking, the higher the hot water output in kilowatts, the better the flow rate will be.

Popular Combi Boiler Brands

Let’s take a look at some of the most popular brands and see how they’re regarded by owners and installers. The scores shown against each manufacturer are taken from the Which? or Trustpilot websites, based on feedback from both installers and householders.

Worcester Bosch | Which? Score: 84%
Reviewers overwhelmingly had a great experience with this company. Customers consistently praise the company's service and products, highlighting their professionalism, efficiency, and knowledge of the engineers. Clear communication, helpfulness, and politeness of staff are also frequently noted.

Hot water flow rate: up to 16.4 l/min
Pros:

• Excellent reliability, highly recommended by Which?
• Parts widely available

Cons:

• Doesn’t work to maximum efficiency unless you use their own controllers
• Some repairs difficult

Common faults: Gas valve seizing, fan failure

Vaillant | Which? Score: 81%
Customers frequently commend engineers for efficient, knowledgeable, and friendly service. Reviewers often note individual engineers' professionalism, clear communication, and quick problem-solving.

Hot water flow rate: up to 15.9 l/min
Pros:

• Boilers very popular with users and engineers
• Easy to work on and parts widely available
• Excellent build quality and reliability

Cons:

• Fairly expensive
• Doesn’t work to maximum efficiency unless you use their own controllers

Common faults: Circuit board cutting boiler out, leaking diverter valve

Glowworm | Which? Score: 70%
The majority of reviewers reported highly positive experiences. Customers recognised the efficiency and quiet performance of Glow-worm boilers, frequently noting advantages over previous models or competing brands.

Hot water flow rate: up to 12.5 l/min
Pros:

• Cheaper to buy
• Good reliability

Cons:

• Build and component quality rated lower than other manufacturers
• Doesn’t work to maximum efficiency unless you use their own controllers

Common faults: Leaking diverter valve, circuit board failure

ATAG | Trustpilot Score: 4.8/5
Most reviewers report an excellent experience. Customers frequently commend the quality of products, pointing out efficient and quiet operation. Buyers also note reliability and a noticeable drop in energy costs.

Hot water flow rate: up to 16.1 l/min
Pros:

• High-quality parts
• Long warranty, lifetime warranty on main heat exchanger
• Heat recovery system for hot water adds efficiency

Cons:

• Historic problems with parts availability and aftercare (recently addressed)

Common faults: Unknown

Ideal | Which? Score: 77%
Ideal’s Logic and Vogue ranges run more cheaply than the average model. Most owners are satisfied, with a four-star customer rating.

Flow rate: up to 16 l/min
Pros:

• Very popular brand at an affordable price

Cons:

• Difficult to connect to the most efficient controllers
• Can become unreliable if not properly serviced

Common faults: Sump leaks, ignition problems

Baxi | Which? Score: 74%
Headquartered in Warwick, Baxi is one of the biggest boiler manufacturers in Europe, offering a lot of choice. Users have high satisfaction rates, resulting in a four-star customer score.
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Hot water flow rate: up to 16.4 l/min
Pros:

• Good value

Cons:

• Less well regarded by installers than many other brands
• Doesn’t work to maximum efficiency unless you use their own controllers

Common faults: Fan, burner, circuit board unit failure

Final Thoughts

All manufacturers offer reward schemes to their installers, meaning advice may be influenced by installer loyalty to a brand. Reliability and performance are the fundamental requirements people look for when buying a new boiler, so it’s worth considering the best-performing boiler that fits your budget.
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If you’d like to see how much you’re likely to pay for a new combi boiler, visit our boiler quote page: Fix First Heating Ltd | Quick Quote for Boiler Repairs, Install & Servicing