Boiler FAQ’s

A Boiler is an appliance that heats water to provide a property with central heating and hot water.

A condensing Boiler recovers and reuses heat from exhaust gases, making it more energy-efficient. All modern Boilers in the UK are condensing Boilers.

The main types of Boilers in the UK are Combi Boilers, System Boilers, and conventional (Regular) Boilers.

A Combi Boiler, or Combination Boiler, is a compact unit that heats water directly from the mains when you turn on a tap, so you get hot water on demand without needing a storage cylinder.

A Combi Boiler heats water instantly when you open a hot tap. It pulls cold water directly from the mains, heats it using a heat exchanger, and provides it to your taps or radiators. The Boiler operates on demand, meaning it only heats water when required, making it more energy-efficient.

• Space-saving: Because it Combines a water heater and central heating Boiler into one unit, it saves space in your home.
• Energy-efficient: It heats water directly from the mains on demand, so there is no need to heat and store a large volume of water, which can save on energy bills.
• Quick and easy to install: Fewer external components mean a quicker and less complicated installation.
• Instant hot water: Hot water is provided on demand, so there’s no waiting for water to heat up.

• Limited hot water supply: Since a Combi Boiler provides hot water on demand, it might struggle to supply enough hot water for multiple taps or showers running simultaneously.
• Not ideal for homes with low water pressure: The Boiler’s performance will be affected if the mains water supply has low pressure.

The size of the Combi Boiler you need depends on your hot water usage and the size of your property. It is measured in kilowatts (kW). A qualified heating engineer will assess your needs and recommend the appropriate size Boiler for your home.

The lifespan of a Combi Boiler typically ranges from 10 to 15 years, depending on the brand, model, and how well it is maintained.

You should have your Combi Boiler serviced once a year by a qualified heating engineer to ensure it runs safely and efficiently.

A System Boiler directly heats your central heating system and produces hot water for a storage cylinder. It includes many components required for the heating and hot water System within the Boiler itself, making it quicker and easier to install.

A System Boiler takes water from the mains supply, heats it, and then stores it in a hot water cylinder until it’s needed for taps or radiators. Unlike a Combi Boiler, it doesn’t provide instant hot water. The water is preheated and stored in a cylinder.

• Perfect for larger homes: System Boilers are ideal for homes with more than one bathroom or high hot water usage, as they can simultaneously supply hot water to multiple taps.
• No need for a tank in the loft: As the Boiler contains most of the necessary components, there’s no need for a separate cold water or feed and expansion tank.
• Constant water pressure: Since the water is supplied directly from the mains, the water pressure is generally strong and consistent.
• Efficient heating: They can be very efficient, especially if you have a modern condensing System Boiler.

• Space for the cylinder: You’ll need enough space to house the hot water cylinder.
• Wait time for hot water: If all the hot water in the cylinder is used, you’ll have to wait for it to reheat before more hot water is available.
• Potential for heat loss: Heat can be lost from the hot water cylinder, although this is minimised with modern cylinders and proper insulation.

The size you need depends on the number of bathrooms in your property and your overall hot water demand. It’s best to consult a qualified heating engineer who will assess your needs and recommend the best size.

With proper maintenance, a System Boiler can last around 10 to 15 years, although this will vary depending on the brand, model, and usage.

To ensure it’s running efficiently and safely, you should have your System Boiler serviced once a year by a qualified heating engineer.

A Regular Boiler (or a conventional or heat-only Boiler) provides heating and hot water through a central heating system and stores hot water in a cylinder. It requires a cold water storage tank, typically in the loft, and a separate hot water cylinder, usually in an airing cupboard.

A Regular Boiler heats water through gas, oil, or electricity-powered heat exchangers. The heated water is circulated through the central heating System, and a portion is stored in a hot water cylinder for use when needed. Cold water is supplied from a tank in the loft, which refills as the hot water is used.

• Ideal for homes with multiple bathrooms: Regular Boilers can supply hot water to multiple taps simultaneously without losing pressure.
• Compatible with older heating Systems: They are often suitable for homes with older radiators and pipes, as they operate under low pressure.
• Good water pressure: If your home has low mains water pressure, a Regular Boiler can still provide strong water pressure.

• Takes up more space: You need space for the separate hot water cylinder and cold water storage tank.
• Delay in hot water: Hot water may not be instant as you have to wait for it to heat up and be stored in the cylinder.
• Potential heat loss: Heat can be lost from the hot water cylinder, although this is minimised with proper insulation.

The size you need depends on the number of bathrooms and your property’s overall hot water and heating demand. A qualified heating engineer will assess your needs and recommend the best size.

With proper maintenance, a Regular Boiler can last around 10 to 15 years, although this will vary depending on the brand, model, and usage.

It is recommended to have your Regular Boiler serviced once a year by a qualified heating engineer to ensure it runs safely and efficiently.

Boilers run on various fuels, including natural gas, oil, electricity, and LPG (liquefied petroleum gas).

Gas Boilers burn natural gas to produce heat. The gas is ignited in the Boiler’s combustion chamber, which heats water or produces steam for heating. They are known for their efficiency and are one of the most common types of Boilers.

• High efficiency: Modern gas Boilers are very efficient, with many models achieving efficiency levels of 90% or higher.
• Lower cost: Natural gas is less expensive than electricity and oil.
• Convenient: Gas is supplied directly to many homes, so there’s no need to store fuel.
• Environmentally friendly: Natural gas burns cleanly and produces fewer greenhouse gases than oil.

Dependency on the gas network: If your home is not connected to the gas grid, installing a gas Boiler won’t be feasible.

Potential for leaks: Gas leaks, though rare, can be dangerous.

Oil Boilers operate by burning oil to heat water. The oil is stored on-site in a tank and needs to be refilled regularly.

• Suitable for off-grid locations: Oil Boilers are popular in areas without a gas connection.
• High efficiency: Modern oil Boilers offer high efficiency, similar to gas Boilers.

• Storage space required: You need space to store the oil tank.
• Price fluctuations: Oil prices can be volatile, affecting your heating costs.
• Less environmentally friendly: Burning oil produces more greenhouse gases than natural gas.

Electric Boilers use electricity to heat water, which then provides central heating and hot water.

• Compact: Electric Boilers are typically smaller than gas or oil Boilers.
• Easy installation: They usually have less complicated installation processes.

Higher running costs: Electricity is more expensive than gas or oil.

LPG Boilers operate similarly to natural gas Boilers, but they use liquefied petroleum gas instead of natural gas. LPG is stored in tanks on the property.

Option for off-grid homes: Like oil Boilers, LPG Boilers are suitable for homes not connected to the gas grid.

Cleaner than oil: LPG burns cleaner than oil, producing fewer pollutants.

• Storage required: You need space to store the LPG tank.
• Higher running costs: LPG is usually more expensive than natural gas.
• Need for deliveries: LPG must be delivered and stored, which requires planning.

It’s recommended to service your Boiler annually to ensure it’s operating safely and efficiently.

A Boiler Service includes checking and cleaning the components, safety checks, and performance checks.

Common signs include strange noises, leaks, pressure drops, or inconsistent heating.

Regular servicing, insulating your home, and using a programmable thermostat will help improve efficiency.

On average, the cost ranges from £1,500 to £3,500, including installation.

Boiler efficiency is rated as a percentage, and modern Boilers in the UK should have an ”A” efficiency rating of 92% or higher.

Loss of pressure could be due to a leak in the System, a faulty pressure relief valve, or a problem with the expansion vessel.

Banging noises can be caused by air in the System, limescale build-up, or an issue with water flow.

Check the basics like power supply and pressure levels, and try resetting the Boiler. If the issue persists, call a gas engineer.

A Boiler leaking water could indicate a serious issue, such as a broken valve or seal, and should be inspected by a gas engineer immediately.

This could be due to low water pressure, a faulty thermostat, a faulty thermocouple or inadequate water flow. A heating engineer will diagnose and fix the issue.

A whistling noise, often referred to as “kettling,” could be caused by limescale build-up in the heat exchanger, which is a serious issue that requires immediate attention.

If you have a Combi Boiler, this could be due to an insufficient flow rate for your needs. For System Boilers, the hot water cylinder may be too small.

Check the pressure gauge, and if it’s above the recommended level, you may need to bleed your radiators or release water via the System’s pressure relief valve. If in doubt, call a gas engineer.

Repressurise your Boiler as per the manufacturer’s instructions.

Follow the manufacturer’s instructions or consult a gas engineer, as the process can vary depending on the Boiler model.

A well-maintained Boiler should last around 10-15 years, though this can vary depending on the model and usage.

Frequent breakdowns, inefficiency, old age, and availability of spare parts are signs that it might be time to consider a Boiler replacement.

Your installation engineer should dispose of your old Boiler safely, or you can contact your local council for disposal advice.

Ensure it’s serviced Regularly, check the pressure, bleed the radiators, and ensure the condensate pipe is insulated.

Boilers are commonly installed in kitchens, utility rooms, or airing cupboards. The location should be easily accessible for maintenance, have adequate ventilation, and comply with safety regulations.

The time required depends on the job’s complexity, but a straightforward replacement will often be completed within one day.

It’s usually necessary for someone to be at home during the installation to provide access and discuss any requirements with the engineer.

Replacing an inefficient Boiler with a new, high-efficiency model can significantly reduce your energy bills.

Yes, many Boilers are compatible with smart thermostats and controls, which can provide greater control over your heating and potential energy savings.

Some of the most reputable brands include Worcester Bosch, Vaillant, Veissman, Potterton, and Baxi. There are various other reputable brands also.

Consider factors like the size of your home, your hot water needs, warranty offers, and reviews from other customers. A gas engineer will help you choose the best model for your situation.

A Gas Safe registered engineer must carry out boiler installation to ensure safety and compliance with regulations.

Modern Boilers should have safety features such as overheating cutoff switches, pressure relief valves, and flame failure devices.

Warranties vary by manufacturer and model, typically ranging from 2-12 years, covering faults and certain parts.

Regular servicing, timely repairs, and proper usage will help extend your Boiler’sBoiler’s lifespan.

Boiler cover will provide peace of mind and save on unexpected repair costs. Still, it’s essential to read the terms and conditions carefully before signing up and follow them to ensure the cover is valid.

Yes, many Boiler installation companies offer financing options so you can pay your Boiler off over time instead of in one lump sum.

In most cases, you do not need planning permission for Boiler installation, but there can be exceptions, such as in listed buildings.

Boilers must be installed by a Gas Safe registered engineer and meet specific energy efficiency and safety standards.