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Combi Boilers

In Need of a New Combi Boiler?

But can’t decide on which boiler best suits your needs?
10 year bosch boiler guarantee

Choosing the right boiler can be the difference between a successful installation and a complete disaster. If your current boiler has given up altogether and without warning, you may be seeking an urgent remedy. Although you may want to get your hot water and heating back up and running as soon as possible. it is important to make the right choice for both your home and your pocket. 

Why Choose a Combi Boiler for Your Home?

Combi boilers are a smart pick for many homeowners. Here's why:

  1. Instant Heating and Hot Water: Combi boilers use mains water to heat your home and provide hot water almost instantly. No need for bulky tanks or containers, saving you space, especially if you have limited room for a hot water cylinder.
  2. Unlimited Hot Water: Since combi boilers draw water directly from the mains supply, you get an endless stream of hot water whenever you need it. Plus, they're quick to install. Our BOXT engineers can have you set up and running in just a day in most cases.

Ready to upgrade to a combi boiler? Get in touch! Gasworks are here to help you make the right decision, our guide to combi boilers is designed to give you a better understanding.

Browse Our  Range Of Worcester Bosch Combi Boilers.

Worcester Bosch has over 50 years of experience in making top-notch boilers. Known for their quality and energy efficiency, Worcester Bosch combi boilers are a reliable choice for your home. Our BOXT engineers specialize in installing Worcester combi boilers, and we provide a 10-year warranty for added peace of mind.

Discover our range of Worcester Bosch combi boilers and enjoy reliable heating and hot water for your home.

Trusted Quality


Get a Free Combi Boiler Quote

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Worcester Bosch 30kW

German Engineering Quality

Gas Combi boiler + flue kit
FREE 10 year warranty
Expertly installed
FREE Bosch Magnetic filter
FREE system cleanse
FREE Scale reducer
FREE pipe upgrade (if required)

ideal logic 30kw combi boiler

Ideal Logic 30kW

The Only Combi Made for Ireland

Gas system boiler + flue kit
FREE 7 year warranty
Expertly installed
FREE Adey Magnetic filter
FREE system cleanse
FREE scale reducer
FREE pipe upgrade (if required)

glow-worm combi boiler

Glow-worm Combi 30kW

Ultra Quiet Combi Boiler

Gas Combi boiler + flue kit
FREE 7 year warranty
FREE system cleanse
Expertly installed
FREE Magnetic filter
FREE system cleanse
FREE scale reducer
FREE pipe upgrade (if required)

What is a Combi Boiler

A Combination boiler, also known as a combi boiler is a popular boiler choice for small to medium sized homes throughout Ireland. The main advantage of a combi boiler is the capability to heat the domestic hot water on demand. While at the same time meeting the property's heating requirements.

It does all this without the need for bulky hot water storage cylinders and tanks, Gas Combi boilers are available for both LPG and Natural Gas, with models also available for oil fired and electrical heating systems.


Why Choose a Combi Boiler? 

Although combination boilers are not the popular boiler choice in Ireland. There are several reasons why choosing a combi boiler makes perfect sense.  

Ideal for apartments and smaller homes, they offer space saving benefits when compared to traditional heating boiler systems. With no bulky hot water cylinder required. 

They produce hot water on demand, meaning there's waiting around for the water to heat. Removing the need to worry about timers or immersion heaters. This will also reduce energy wastage as you only heat what you use. 

Like pressure?. In Ireland poor water pressure is a common occurrence. Combination boilers operate at a higher pressure than traditional gravity feed hot water systems. Resulting in more flow at the tap. 

Important Considerations

As much as you may like the idea of instant hot water, combi boilers are not an ideal fit for every home.

If your home is quite large with several bathrooms, en-suites etc a combination boiler may not be the right choice. One of the most common combi problems we encounter is the lack of hot water when more than one hot water outlet is in use. Because combi's heat the water instantly, the amount of hot water produced may not be able to keep up with demand. For example, if you have more than 1 shower operating at the same time. Because of this combi boilers are not recommended for homes with more than one bathroom. 

Mains Water Pressure.

The incoming water mains is not sufficient or erratic. Because combi boilers require a min flow rate to operate, if your mains water is to weak a booster pump and break tank will be required. This will increase installation and maintenance costs 


Still thinking of installing a combi boiler? Get a fixed price quotation 


Combi Boilers Vs Regular Boilers


Pros & Cons of a Combi Boiler

For the average small sized homes with 1 bathroom, a combi boiler offers several advantages:


  1. Efficient: Combi boilers provide hot water on demand, eliminating the need to heat and store a cylinder of water constantly. This makes them highly efficient.
  2. Energy-saving: Heating water only when needed reduces energy consumption, making combi boilers more eco-friendly and cost-effective.
  3. Space-saving: Combi boilers are compact and consist of just one unit, fitting well in most kitchens and can even be concealed behind cupboards.
  4. Cost-effective: The on-demand heating method saves energy, leading to lower heating costs over time.
  5. Easier Repairs: Spare parts for modern combi boilers are often readily available, simplifying and speeding up the repair process.


  1. Not Suitable for Larger Homes: Combi boilers may struggle to meet the high demand for hot water in larger homes.
  2. Dependent on Mains Water Pressure: Homes with weak mains water pressure may not be suitable for combi boilers.


Pros & Cons of a System/Regular Boiler

For larger homes with more than 1 bathroom a system/regular boiler offers its advantages and disadvantages:


  1. Meets High Demand: Conventional boilers can supply multiple areas of the home with hot water simultaneously, keeping up with high demand.
  2. Well-suited to Larger Homes: Larger homes with existing conventional boiler systems may find it more cost-effective to maintain rather than replace them.


  1. Requires Space: Conventional boilers require ample storage and installation space, including insulation to prevent heat loss.
  2. Delayed Hot Water: Users may experience delays in accessing hot water if the cylinder runs out and needs reheating.
  3. Complex Maintenance: Conventional boilers have more components and controls, requiring regular maintenance and posing potential risks of leaks and damage.

Costs of Converting to a Combi Boiler from a System/Regular Boiler

Converting from a conventional to a combi boiler can cost between €3,500 and €4,800, including the installation of a reputable brand like Worcester Bosch. While the initial cost may be high, the long-term benefits include improved efficiency and lower energy bills.

Upgrade to a Combi Boiler with Gasworks.ie

If you're considering upgrading from a conventional boiler to a combi boiler, our team of expert boiler engineers at Gasworks can assist you. We'll assess your home size, hot water usage, and priorities to determine the best combi boiler system for your needs. Contact us today to discuss your options and boost your home's efficiency and cost savings.

For more information, please visit our website or reach out to us directly.


What Size Combi do you need?

Choosing the Right Boiler Size for Your Home

When it comes to selecting the right boiler size for your home, there are several factors to consider, including your hot water needs, the size of your home, and the number of radiators. Here's a breakdown to help you find the perfect fit:

2 Bedroom Homes/Apartments

  • Ideal for individuals or small families living in homes or apartments with one to two bedrooms, one bathroom, and up to ten radiators.
  • Choose a combi boiler with an output between 24-30kW to meet your heating and hot water needs efficiently.

3 Bedroom Homes:

  • Suitable for medium-sized semi-detached houses with three to four bedrooms, one to two bathrooms, and up to 14 radiators.
  • Consider a boiler with an output between 30-35kW to ensure ample heating and hot water supply for your household.

Large 4-Bedroom Homes:

  • Perfect for large families with high hot water demand residing in spacious semi-detached or detached houses with over four bedrooms, over two bathrooms, and up to twenty radiators.
  • Choose a Combination boiler with an output of 35-40kW to meet your  homes heating and hot water needs effectively.

Count Your Radiators:

  • Counting the number of radiators in your home can help determine the appropriate boiler size. Generally, more radiators require a larger boiler to provide sufficient heating power.
  • For example:
  • Up to 10 radiators: 24–27 kW
  • 10 to 15 radiators: 28–34 kW
  • 15 to 20 radiators: 32–40 kW

Avoid Oversizing:

Oversizing your boiler can lead to wasted energy and higher fuel bills. Choose a boiler size that meets your needs without excess capacity.

5 Important Factors 

What are five most important factors in your decision-making process?

Price, Efficiency, Warranty, Reliability, Quality Installer are probably the most influential factors to decide from. 


The single most important decision is the cost. Prices can vary hugely, depending on the installation difficulty and choice of boiler. It is for this reason it is important to get at least 3 estimates.  


With so many different boilers brand available on the market today it may be difficult to decide which is best. Although a certain brand may be very popular in Ireland, this does not guarantee quality. Think Celtic Tiger Houses, the most important factor for many builders was maximum profits. Nobody ever questions the central heating boiler when buying a brand-new house. But you Should!  


The longer the warranty the better the deal and usually the better the boiler. It is important to ensure that any warranty given is backed up by the boiler manufacturer. Ensure you receive a copy of the warranty documentation including all relevant terms and conditions. 


The better the reliability the better the boiler. Worcester Bosch are the market leaders when it comes to reliability. But don’t believe us check it out for yourself here 


Although manufacturer accredited installers are always the best choice. It is important to research online reviews to ensure they are both genuine and positive. Don’t be afraid to ask for references if your still unsure. RGI Registered is not only a must its illegal for anyone other than an RGI.  

Insulation Quality

The level of insulation in your home impacts its heating efficiency. Poor insulation may necessitate a higher output boiler.


The amount of hot water your home uses will have a direct impact on the required boiler size. Likewise, the heating demands for your home will also have a bearing on the boiler size. 

The bigger the hot water output, the higher the flow rate. It is important to remember the incoming cold mains water pressure, will also need to be capable of matching the flow rate output of the boiler. 

With so many different factors affecting the boiler size, it is best to seek expert advice. 

Our Team of expert heating advisors are available to assist you simply call 01-4433005 .


How Long Does a Combi Boiler Last?

Modern combi boilers are designed to last up to 15 years, thanks to their high efficiency and reduced pressure issues compared to conventional boilers. However, the lifespan of your boiler depends on various factors, including the model's quality and how well you maintain the system.

Tips to Increase Boiler Life Expectancy:

    1. Annual Servicing: Schedule an annual service with Gasworks. Our Expert Boiler Engineers will ensure your boiler runs efficiently and detect any early signs of damage, helping to prevent costly repairs. Even if your boiler seems fine, regular servicing is key to prolonging its lifespan. Don't forget annual servicing is essential to maintain the boiler guarantee too.
  1. Prevent Corrosion: Over time, boilers can be vulnerable to rust and corrosion, which can lead to damage. Adding an inhibitor to your system creates a protective coating around the metal, preventing corrosion and limescale build-up. While an inhibitor doesn't eliminate existing limescale, it serves as a preventive measure. If your system already suffers from corrosion, sludge, and limescale, a powerflush may be necessary.
  2. Prevent Sludge Buildup: Sludge and debris accumulation in the central heating system can damage your boiler over time. Installing a magnetic filter, a small device placed within the pipework, helps filter out sludge before it reaches the boiler. During your annual service, a GSR engineer can install and clean the magnetic filter, ensuring your boiler's longevity.

By following these maintenance tips and investing in quality servicing, you can extend the life of your combi boiler and keep your central heating system running smoothly for years to come. If you have any questions or need assistance with your boiler, don't hesitate to contact us. Our team of experts is here to help you maximize the lifespan and efficiency of your heating system.


Should You Replace Your 10-Year-Old Boiler?

Deciding whether to replace a boiler can be challenging. Replace it too soon, and you might discard a perfectly functional unit. Wait too long, and you risk sudden breakdowns and emergency repairs. So, how do you know when it's time for a replacement?


Signs Your Boiler Needs Replacing


  1. Decreased Efficiency: Older boilers tend to be less efficient than newer models. As they age, they become less reliable and may contribute to higher gas bills. If you've noticed a spike in your gas costs, your aging boiler could be the culprit. Newer models often require less gas to achieve the same heating outcomes, leading to potential savings.
  2. Unusual Noises: Listen for strange sounds like groaning, clanging, tapping, or hissing coming from your radiators, pipes, or boiler. These noises can indicate underlying issues, such as sludge or limescale build-up, reducing system performance. Flushing the central heating system can help remove contaminants and restore proper flow. Severe cases may require boiler component replacements.
  3. Flame Colour: Check the colour of the boiler flame. A blue flame indicates proper burning, while an orange or yellow flame suggests combustion issues. Incorrect burning can lead to carbon monoxide production, posing a safety hazard.


When to Seek Professional Advice

If you've noticed any of the above signs, it's wise to consult a heating engineer for an expert opinion. However, if your 10-year-old boiler is still operating smoothly without unusual noises or flame colour changes, it may not require immediate replacement.


Maintenance Tips for Aging Boilers


  • Regular Servicing: Continue scheduling annual boiler services to ensure optimal performance and catch any potential issues early.
  • Vigilance: Stay alert for signs of deterioration, such as increased noise levels or changes in flame colour, and address them promptly.

By staying proactive and attentive to your boiler's condition, you can maximize its lifespan and efficiency while avoiding unexpected breakdowns. If you're unsure whether to replace your boiler, our team of heating experts is here to provide guidance and assistance tailored to your needs.


Deciding on Boiler Brand


Types of Combi Boilers in Ireland

Although we’ve listed the best gas Combi boilers here as they’re the most commonly installed, Combi boilers are also available in oil, LPG or electric in a range of sizes. 

Gas Combi Boilers 

Natural Gas Combi Boilers are the most popular combi boiler sold in Ireland. Natural Gas is a cheaper fuel when compared with electricity, oil or LPG. This of course means lower running costs. 

For Nat Gas Boiler Installations always consult an RGI Registered Installer 

Oil Combi Boilers 

Much like their natural gas counterparts oil combi boilers never really took off in Ireland. Although scarce, they do exist. When compared to gas, with oil combis you can expect to pay as much as 40% more in installations costs. Not to mention the running costs will be typically more expensive too. Not forgetting if you are unfortunate to run out of oil, you will be without hot water. Although an inline immersion can be fitted as a backup. This will not provide the equivalent in hot water. 

For Oil Boiler Installation always consult an OFTEC Registered Installer   

LPG Combi Boilers 

Very much the same as natural gas combi boilers, with running costs the main difference. Although costlier per unit than Nat Gas, for homes not on the national gas network LPG may be a wise choice. Liquid Petroleum Gas is available in both bulk storage and bottled supply.   

For LPG Gas Boiler Installations always consult an RGI Registered Installer 

Electric Combi Boilers 

An electric Combi boiler uses an electrical element to heat the water. They are a popular choice for homes where Nat Gas, LPG or Oil is either unavailable or inpractical.

The most obvious downside to electrical boilers is of course the usage costs, which are considerably more than alternative fuels. Electrical boilers are not suited to homes with moderate hot water needs.

Choosing an Installer  

Installation of a combi boiler is a complex specialist task that requires competent engineers/plumbers and in some cases electricians. In Ireland there is plenty of boiler installation companies to choose from. But How do you choose between them?