When Should You Replace Your Boiler?

 

A boiler does not necessarily need replacing simply because it is old. A properly maintained appliance may continue working reliably for many years.

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However, replacement may be the more practical option when:

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• The boiler regularly breaks down.

• Repair costs are increasing.

• Replacement parts are difficult to obtain.

• Heating or hot-water performance has deteriorated.

• The boiler frequently loses pressure.

• Energy consumption appears to be increasing.

• The appliance is excessively noisy.

• The boiler no longer works effectively with modern controls.

• The property has been extended or renovated.

• The household requires more hot water.

• The existing boiler is unsuitable for the heating system.

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Before recommending a new boiler replacement, an installer should establish whether the fault is within the boiler or elsewhere in the system.

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Problems with pumps, valves, thermostats, radiators, circulation, water pressure, sludge or heating controls can sometimes make a functioning boiler appear defective.

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Repair or Replace an Old Boiler?

 

The decision to repair or replace a boiler will depend on its age, condition, reliability and the likely cost of keeping it operational.

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A repair may be sensible where:

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• The fault is relatively minor.

• Replacement parts remain readily available.

• The boiler has otherwise been reliable.

• The appliance continues to meet the needs of the property.

• The heating system is in good condition.

• The expected repair cost is reasonable.

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Replacement may offer better long-term value where the boiler requires repeated repairs, parts are becoming obsolete or the appliance is no longer suitable for the property.

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A professional assessment should consider the complete cost of continuing to maintain the existing boiler rather than looking at one repair bill in isolation.

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Choosing the Right Replacement Boiler

 

A new boiler should be selected for the property rather than automatically matched to the output of the old appliance.

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Some older boilers were oversized when originally installed. Insulation improvements, replacement windows, extensions and changes to the number of radiators may also mean the original boiler specification is no longer appropriate.

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The installer should consider:

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• The size and construction of the property.

• Wall, roof and floor insulation.

• Window and door performance.

• The number and size of radiators.

• Underfloor-heating requirements.

• The number of bathrooms.

• The number of occupants.

• Expected hot-water use.

• Incoming water pressure and flow rate.

• The condition and size of existing pipework.

• The proposed boiler position.

• Flue and condensate arrangements.

• Fuel-supply requirements.

• Heating controls and zoning.

• Planned extensions or property alterations.

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Correct boiler sizing is important. An unnecessarily powerful boiler may cycle on and off frequently, while an undersized boiler may struggle to heat the property or satisfy its hot-water requirements.

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What Type of New Boiler Do You Need?

 

There are several different ways to replace an existing boiler. The best option will depend on the current system and the needs of the household.

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Combi Boiler Replacement

A combination boiler provides heating and instantaneous hot water from one appliance.

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It does not usually require a separate hot-water cylinder or cold-water storage tanks, making it a popular option for flats and smaller or medium-sized homes.

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However, combi boiler performance depends on the incoming mains water pressure and flow rate. Installing a larger boiler cannot compensate for a poor incoming water supply.

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A combi may not be the best option for a larger home where several showers, baths or taps are likely to be used simultaneously.

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System Boiler Replacement

A system boiler works with a separate hot-water cylinder.

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This arrangement can be suitable for larger homes, properties with several bathrooms and households requiring a stored supply of hot water.

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The installer should assess both the boiler and cylinder. Replacing the boiler while retaining an undersized or deteriorating cylinder may limit the performance of the new system.

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Regular Boiler Replacement

A regular, conventional or heat-only boiler normally works with a hot-water cylinder and may also use water-storage tanks within the roof space.

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A like-for-like regular boiler replacement can be appropriate where the existing heating arrangement remains in good condition and continues to meet the household’s requirements.

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However, the cylinder, tanks, pumps, controls and associated pipework should still be inspected.

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Gas Boiler Replacement

 

Gas remains a common source of domestic heating in properties connected to the mains gas network.

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A gas boiler replacement may involve:

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• A like-for-like boiler change.

• Converting a regular boiler to a system boiler.

• Converting to a combi boiler.

• Relocating the boiler.

• Upgrading the gas supply pipe.

• Altering the flue.

• Installing a condensate drain.

• Replacing the hot-water cylinder.

• Removing redundant water tanks.

• Installing new heating controls.

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All gas-boiler installation work must be undertaken by an appropriately qualified Gas Safe registered engineer. Gas Safe Register is the official registration body for gas businesses and engineers, and gas businesses must be registered by law.

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For more information, see the APN Boilers Gas Boiler Replacement page.

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Oil Boiler Replacement

 

Oil boilers are widely used in rural and off-grid properties without access to mains gas.

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An oil boiler replacement should include an assessment of:

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• The boiler output.

• The oil-storage tank.

• The fuel-supply line.

• Fire-safety controls.

• The boiler flue.

• Condensate drainage.

• Existing radiators and pipework.

• Hot-water storage.

• Heating controls.

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OFTEC operates a competent-person registration scheme for oil-heating technicians. Registered installers can self-certify qualifying installation work in England and Wales.

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For more information, see the APN Boilers Oil Boiler Replacement page.

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LPG Boiler Replacement

 

LPG boilers provide heating and hot water for rural homes, park homes and other properties without mains gas.

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Although LPG boilers are similar to mains-gas boilers, the installation also requires specialist knowledge of LPG tanks, cylinders, regulators, supply pressures and fuel pipework.

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The engineer should be Gas Safe registered and hold the appropriate LPG qualifications. Registration for one type of gas work does not automatically qualify an engineer to undertake every type of gas installation.

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For more information, see the APN Boilers LPG Boiler Replacement page.

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Electric Boiler Replacement

 

An electric boiler can provide heating through conventional radiators or underfloor heating without requiring a combustion flue, gas connection or fuel-storage tank.

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Electric boilers may be suitable for:

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• Flats and apartments.

• Smaller homes.

• Properties without mains gas.

• Buildings where a conventional boiler flue cannot be installed.

• Homes with an existing wet central-heating system.

• Properties where installation space is restricted.

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The electrical supply must be assessed before the boiler is selected. Larger electric boilers may require dedicated cabling, suitable circuit protection and alterations to the consumer unit.

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Energy Saving Trust identifies electric boilers as one of several electric-heating options, with suitability depending on the property and its circumstances.

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For more information, see the APN Boilers Electric Boiler Replacement page.

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What Does a New Boiler Replacement Cost?

 

There is no single new boiler replacement cost that applies to every property.

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The price will depend on the boiler, fuel type and complexity of the installation. A straightforward like-for-like replacement in the same position will normally cost less than changing the boiler type, moving the appliance or redesigning the heating system.

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The cost may be affected by:

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• Boiler manufacturer and model.

• Boiler output.

• Fuel type.

• Combi, system or regular arrangement.

• Manufacturer warranty.

• Boiler relocation.

• Flue alterations.

• Condensate drainage.

• Gas, oil, LPG or electrical supply work.

• Hot-water cylinder replacement.

• Removal of storage tanks.

• Heating-system cleaning.

• Magnetic filter installation.

• New heating controls.

• Radiator and valve upgrades.

• Scaffolding or specialist access.

• Electrical work.

• Making good.

• Waste disposal.

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A low headline price may represent only a basic boiler swap. It may not include system cleaning, controls, filters, pipework alterations, certification or remedial work discovered during installation.

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Homeowners should compare quotations on a like-for-like basis rather than selecting a replacement based solely on the lowest price.

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Converting to a Combi Boiler

 

Many homeowners use a boiler replacement as an opportunity to remove a traditional hot-water cylinder and install a combi boiler.

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This can free up space, but it may require substantial alterations to the heating and plumbing system.

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A conversion may include:

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• Removing the hot-water cylinder.

• Removing roof-space storage tanks.

• Altering heating flow and return pipes.

• Installing new hot- and cold-water pipework.

• Upgrading the fuel supply.

• Providing a new condensate drain.

• Altering the flue arrangement.

• Replacing pumps and valves.

• Installing new controls.

• Testing the incoming water supply.

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The water pressure and flow rate should be tested before a combi boiler is selected.

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A combi conversion may work well in a smaller home, but retaining stored hot water can provide better performance in a larger property with several bathrooms.

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Check the Existing Heating System

 

A new boiler cannot correct every fault within an old or poorly designed central-heating system.

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Before installation, the engineer should inspect:

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• Heating flow and return pipework.

• Radiator sizes.

• Thermostatic radiator valves.

• Pumps and zone valves.

• Expansion vessels.

• Hot-water cylinders.

• Existing thermostats.

• System water quality.

• Signs of corrosion or sludge.

• Fuel or electrical supplies.

• Flue and condensate routes.

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Installing a new boiler onto a contaminated or poorly balanced system can reduce heating performance and place unnecessary strain on the new appliance.

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The installer should recommend an appropriate system-cleaning and water-treatment process.

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Improve Your Heating Controls

 

A boiler replacement provides an opportunity to improve how the complete heating system is controlled.

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Suitable upgrades may include:

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• Programmable room thermostats.

• Smart thermostats.

• Thermostatic radiator valves.

• Separate heating zones.

• Hot-water timing.

• Weather compensation.

• Load compensation.

• App-based controls.

• Individual room temperature control.

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Modern heating controls can help homeowners heat rooms when required and avoid unnecessary energy use. Energy Saving Trust advises that programmers, thermostats and radiator controls form an important part of managing boiler-based heating systems.

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The controls should be selected for the boiler and system rather than treated as an unrelated accessory.

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Boiler Efficiency and System Design

 

Modern condensing boilers recover heat that would otherwise be lost through the flue, making them more efficient than many older boiler designs.

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However, the efficiency of the installation also depends on:

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• Correct boiler sizing.

• Suitable flow temperatures.

• Balanced radiators.

• Effective heating controls.

• Clean system water.

• Appropriate radiator outputs.

• Adequate insulation.

• Regular servicing.

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A new boiler replacement will provide the best result when the appliance, controls, radiators and pipework operate together as a properly designed system.

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Boiler Position, Flue and Condensate Drainage

 

The existing boiler position may remain suitable, but this should be checked before the replacement is ordered.

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The installer should consider:

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• Access for installation and servicing.

• Flue clearances.

• Windows and doors.

• Boundaries and neighbouring properties.

• Roofs, extensions and passageways.

• Condensate drainage.

• Manufacturer installation requirements.

• The external appearance of the flue.

• The route of fuel and heating pipework.

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Moving the boiler may improve the use of space within the property, but it will normally increase installation work and cost.

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Building Regulations and Certification

 

New and replacement heating installations must comply with the applicable Building Regulations, including requirements relating to energy efficiency and building services. Approved Document L provides the relevant energy-performance guidance for new and existing dwellings in England.

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Where a Gas Safe registered business installs a new gas boiler, the installation should be notified and the homeowner should receive a Building Regulations Compliance Certificate. The certificate belongs with the property and may be required when it is sold or remortgaged.

Oil-boiler installations completed by suitably registered OFTEC competent persons can also be self-certified where the work falls within the scheme.

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Homeowners should retain:

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• The Building Regulations Compliance Certificate.

• Boiler commissioning documentation.

• Manufacturer warranty details.

• Installation instructions.

• Control instructions.

• Service records.

• Details of any system-cleaning treatment.

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Should You Consider a Heat Pump?

 

Before replacing a gas, oil or LPG boiler with another fossil-fuel appliance, some homeowners may wish to compare the installation with a heat pump.

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A heat pump is not necessarily a direct like-for-like boiler replacement. The property may require:

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• A room-by-room heat-loss calculation.

• Larger radiators.

• Changes to heating pipework.

• Improved insulation.

• A hot-water cylinder.

• Space for an external unit.

• Electrical-supply alterations.

• Different heating controls.

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The Boiler Upgrade Scheme can provide support to eligible property owners in England and Wales who replace qualifying fossil-fuel or electric heating systems with a low-carbon heating system.

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The decision should be based on the property, installation cost, expected running costs, heating requirements and the homeowner’s long-term plans.

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What Should a Boiler Replacement Quotation Include?

 

A clear quotation should identify:

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• The boiler manufacturer and model.

• Boiler type and output.

• Fuel type.

• Proposed location.

• Manufacturer warranty.

• Flue arrangement.

• Condensate route.

• Required fuel-supply work.

• Electrical requirements.

• Heating controls.

• System cleaning and treatment.

• Magnetic filter.

• Cylinder, radiator or valve alterations.

• Removal of the old boiler.

• Commissioning.

• Building Regulations notification.

• Making good.

• Waste disposal.

• VAT.

• Any exclusions or provisional costs.

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The installer should explain why the proposed boiler is suitable and how its output has been selected.

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Find a New Boiler Installer Through APN Boilers

 

APN Boilers brings together experienced boiler and heating professionals serving homeowners across the UK.

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The APN network focuses on more than simply replacing the appliance. The aim is to provide a boiler that is properly selected, correctly installed and integrated with the heating and hot-water system.

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Whether you need a gas, oil, LPG or electric boiler replacement, tell APN Boilers about your property, existing boiler and heating requirements.

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We will help you find an appropriate local professional for your new boiler replacement.

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