New Conventional Boiler Installation - Regular, Heat-Only & Open Vent

Conventional boilers (also known as regular, heat-only or open vent boilers) are designed to provide both heating and hot-water with the use of an additional cold-water tank and hot-water cylinder. These boilers could be particularly suitable for households where multiple people are likely to require hot-water at the same time.

Here at HomeServe, we supply a range of conventional boilers and it is our aim to help you select the right boiler for your home. Our online free quote tool could provide you with a personalised quote for the installation of your new conventional boiler. Give it a try – it could take just 30 seconds!


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How Does A Conventional Boiler Work?

Conventional boilers are often regarded as the traditional form of central heating. These boilers use a cold-water tank and a hot-water cylinder for storage, which both tend to be installed into loft spacing. Once the fuel has been ignited, the heat exchanger warms water which is then transported to the hot-water storage tank by a pump. This stored hot-water is then sent to your taps and radiators when you need it.

Regular boilers are also built with an expansion vessel, which is used to keep the pressure constant by controlling the heated water as it expands; this helps prevent pumps and pipes from bursting. A feed and expansion tank is additionally required in order to help maintain your heating system’s water levels; it could also be used to store extra hot-water.


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Advantages of a Conventional Boiler

Heat-only boilers supply a variety of homes with heating and hot water, providing you with a number of potential benefits. These include:


They’re designed to provide hot-water to multiple taps simultaneously

Conventional boilers could be a great choice for you if you have a high demand for hot water or if you have multiple bathrooms, as these boilers are designed to deliver hot-water to numerous taps simultaneously.

Often quick, easy and cost-effective to install

If your home already has a traditional central heating system, installing a new conventional boiler could be a quick and easy task. It could also be cheaper as a change in boiler type require additional parts and labour.

They could be fitted with an additional electrical immersion heater

These devices are designed to provide you with a back-up in case your boiler ever suffers a breakdown. With an immersion heater you could still have access to hot water even if your boiler is on the blink, as they run off of electricity as opposed to gas or oil. This could be one of the main advantages of installing a conventional boiler, as some other boiler types typically don’t have this feature.


The conventional boilers that we supply at HomeServe are all A-rated for efficiency. With boilers from top brands such as Worcester Bosch, Vaillant and Ideal, we could help your lower your energy bills by potentially reducing your energy wastage.

The open-vent boilers that we stock are manufactured by leading brands in the industry, who design their boilers to be top-quality, reliable and energy-efficient.

Worcester Bosch Logo

A leading boiler brand in the domestic heating industry since 1962.

  • Products rated Which? Best Buys for 8 years running
  • Boilers designed to be premium quality
  • Products receive top scores for efficiency, reliability and engineer recommendation (Which)

Find out more about Worcester Bosch boilers here.

Ideal Logo

This brand has been striving to provide homeowners with reliable, energy-efficient boilers since 1906.

  • Good Housekeeping Reader Recommended
  • Over 100 years of industry experience
  • Boilers rated 5 stars for energy-efficiency

Find out more about Ideal boilers here.

Vokera Logo

Dedicated to providing homeowners with reliable heating solutions.

  • Products receive top scores for energy-efficiency
  • H & V News Award Nominated for Domestic Heating Product of the Year
  • Up to 7 years’ manufacturer backed warranties

Find out more about Vokera boilers here.

Vaillant Logo

This brand aims to provide homeowners throughout the UK and Ireland with an energy-efficient way of heating their homes.

  • Extensive Industry Experience
  • 5-star brand customer score (Which?)
  • Boilers receive top scores for ease of repair, ease of service, and build quality (Which?)

Find out more about Vaillant boilers here.

Baxi Logo

This West Midland’s brand has been manufacturing domestic heating products since 1866.

  • Products receive high scores for efficiency and ease of service
  • Over a century’s worth of industry experience
  • Awarded by the Gas Safe Awards 2017 for their energy-efficiency

Find out more about Baxi boilers here.


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Most Popular Conventional Boilers

1. Worcester Bosch Greenstar 15Ri

  • Compact size to potentially fit into a standard kitchen cupboard
  • A-rated for energy-efficiency
  • Built-in frost protection
  • 600mm x 390mm x 270mm (height x width x depth)
  • Typically best suited to most small to medium-sized homes with up to 6-8 radiators and 1 shower room

2. Worcester Bosch Greenstar 18Ri

  • Compact dimensions
  • Built-in heating temperature control
  • Low NOx and CO2 emissions
  • 600mm x 390mm x 270mm (height x width x depth)
  • Typically best suited to most small to medium-sized homes with up to 8-10 radiators and 1 shower room.

3. Worcester Bosch Greenstar 24Ri

  • Simple boiler controls
  • Frost protection
  • Compact in size
  • 600mm x 390mm x 270mm (height x width x depth)
  • Typically best suited to most medium-sized homes that have up to 10 radiators and 1 bathroom

4. Ideal Logic Heat H15

  • Back-lit display
  • Easy-to-use pressure gauge
  • Compact in size
  • 700mm x 395mm x 278mm (height x width x depth)
  • Typically best suited to most small to medium-sized homes with up to 6-8 radiators and 1 shower room


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Cost of a Conventional Boiler Installation

“How much could a conventional boiler cost to install?” If this is one of the questions on your mind, we could provide you with a suitable answer. Our online free quote tool is designed to give you a realistic, personalised estimate for your new boiler installation. Factors that are likely to influence the cost of your new conventional boiler installation include the size of your home, your heating and hot-water requirements and the complexity of the installation process (i.e. any additional parts or labour).

Our free online quote tool aims to take these factors into consideration to provide you with an indicative quote for your installation. All you have to do is answer a few simple questions about your home and within a few seconds you could be provided with your free no-obligation quote.


Which conventional boiler do I need in my home?

Here at HomeServe, we aim to supply a range of conventional boilers so that we’re able to meet the needs of a variety of homes. It is our goal to provide you with the help and advice you need to help ensure that the boiler you have installed is able to heat your home effectively and efficiently.

Factors such as your home size and central heating demands will help determine the kW output that you’ll need from your new boiler. A boiler’s kW output influences its ability to cope with your central heating needs and tends to be based on the number of radiators and bathrooms that you have in your home.

For example, if you choose to install a boiler that has a higher kW output, you could receive a higher the supply of hot-water. However, this does not mean that you should purchase a boiler with the highest output available, you must ensure that your boiler’s size matches the size and requirements of your home.

The estimated guide below could help you get a better idea about the kW output that your home may require:

12-15kW 1-3 bedrooms, 1 bathroom
18-24 kW 3-4 bedrooms, 1-2 bathrooms
30kW + 4 or more bedrooms, 2+ bathrooms


(This information has been supplied By Help-Link UK limited and has been produced for information purposes only and should not be used or relied upon as a substitute for professional advice by a suitably qualified engineer.)

If you’re looking for a conventional boiler for your home, our expert team could provide you with the help and advice you need to make a suitable decision. Our Gas Safe engineers could also conduct a thorough and professional installation of the boiler that you choose.

Try our free no-obligation quote tool to receive an estimate of the cost of your new conventional boiler installation and our team will aim to get in touch with you as soon as possible to help get you to the next step.


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*Online discount is available to domestic gas and LPG customers who receive an online quote for all boiler brands excluding Ideal Logic HO18 & HO24 & like-for-like system swaps on the Ideal Logic HE24 and HE30, and Ideal Logic HO12 & HO15 boilers. Discount will be applied as long as the quoted price is still applicable at the point of sale. Online discounted price is only available for the duration of the 14-day quote validity which starts from the day the quote was given. Offer is not available to HomeServe employees. | All boiler manufacturer types on like-for-like system swaps excluding the following boilers: Ideal Logic HE24 & HE30, Ideal Logic HO12, HO15, HO18 & HO24 are eligible for a £50 discount and then 5% discount off the final quoted price. Conventional to combi boiler swaps also qualify for an additional £100 discount after 5% initial discount is applied. This offer cannot be used in conjunction with any other offers. HomeServe have the right to withdraw or change the offer at any time. Online discount is automatically applied when the customer gets a quote using the online quote system at and as long as the customer meets all the above criteria.

Source: Saving calculated when replacing G rated with A rated boiler in a semi-detached house.