When Should You Replace an Electric Boiler?

 

Electric boilers contain fewer combustion-related components than gas or oil boilers, but they can still become unreliable or unsuitable as they age.

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An electric boiler replacement may be required when:

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• The boiler regularly loses pressure or stops heating.

• Heating takes longer than it previously did.

• The boiler is producing fault codes.

• Replacement parts are becoming difficult to obtain.

• The existing boiler is incorrectly sized.

• Household heating or hot-water requirements have changed.

• The property has been extended or renovated.

• New heating controls are being installed.

• The boiler is no longer economical to repair.

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Before replacing the appliance, the installer should determine whether the fault is within the boiler or elsewhere in the heating system.

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Problems with pumps, controls, valves, radiators or circulation can sometimes make a working boiler appear defective.

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Choosing the Right Electric Boiler Replacement

 

Replacing an electric boiler should not simply involve fitting a new appliance with the same output as the old one.

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The boiler should be selected following an assessment of the property’s heat loss, insulation, radiator sizes and expected heating demand.

 

An undersized boiler may struggle to heat the property, while an unnecessarily large unit could place excessive demands on the electrical installation.

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The assessment should consider:

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• The size and construction of the property.

• Wall, floor and roof insulation.

• Window performance.

• The number and size of radiators.

• The existing heating pipework.

• Whether underfloor heating is installed.

• Hot-water requirements.

• Available electrical capacity.

• The position of the consumer unit.

• Heating zones and controls.

• Planned extensions or property alterations.

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Correct boiler sizing is particularly important with electric heating because the electrical supply must be capable of supporting the proposed appliance.

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Checking the Electrical Supply

 

An electric boiler can require a substantial dedicated electrical supply. The suitability of the consumer unit, incoming supply, protective devices and electrical cabling should therefore be checked before a replacement boiler is ordered.

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Depending on the output and type of appliance, the installation may require:

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• A dedicated electrical circuit.

• New supply cabling.

• Suitable circuit protection.

• A local isolation switch.

• Consumer-unit alterations.

• Confirmation of the available incoming electrical capacity.

• Coordination with an electricity network operator or supplier.

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Manufacturer installation guidance requires electric boiler circuits and protective equipment to comply with current electrical-installation requirements. Electrical work should be completed by a suitably qualified and competent electrician.

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The cost of any necessary electrical work should be identified during the quotation stage rather than after the boiler installation has begun.

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Electric Boilers and Wet Central Heating

 

An electric flow boiler heats water which circulates through a wet central-heating system. This means it can often work with standard radiators, thermostatic radiator valves, pumps, programmers and underfloor-heating systems.

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Where the existing radiators and pipework are in good condition, an electric boiler replacement may not require the complete heating system to be changed.

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However, the installer should still inspect:

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• Radiator sizes and heat output.

• The condition of existing pipework.

• System pressure.

• The circulation pump.

• Expansion vessels.

• Zone valves.

• Thermostatic radiator valves.

• Signs of corrosion or sludge.

• The effectiveness of the existing controls.

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The system may need flushing and cleaning before the new boiler is commissioned. Inhibitor should also be added where appropriate to help protect the boiler, pipework and radiators.

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Heating and Hot-Water Arrangements

 

Not every electric boiler provides hot water in the same way.

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Some electric boilers are designed primarily to supply central heating and work with a separate hot-water cylinder. Other combined systems incorporate an electric flow boiler, cylinder, circulating pump and controls within one unit.

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The correct arrangement will depend on:

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• The number of occupants.

• The number of bathrooms.

• Shower and bath usage.

• Available storage space.

• The incoming water supply.

• Whether simultaneous hot-water use is expected.

• The household’s daily routine.

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A small electric boiler may be suitable for heating a compact flat but may not satisfy the hot-water demands of a larger family home. Boiler and cylinder sizes should therefore be assessed together.

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Benefits of Replacing an Electric Boiler

 

A modern electric boiler can offer several practical advantages:

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• No gas connection is required.

• No oil or LPG storage tank is needed.

• No combustion flue is required.

• The appliance can be compact.

• Installation locations may be more flexible.

• Existing radiators may often be retained.

• There are no on-site combustion emissions.

• Heating can be controlled using modern thermostats and zoning.

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The absence of a flue can make electric boilers particularly useful in flats, internal rooms and properties where conventional flue positioning is difficult.

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Electric Boiler Running Costs

 

Electric boilers convert electricity directly into heat within the property, but this does not necessarily make them the least expensive heating option.

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The overall running cost depends on:

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• The electricity tariff.

• The property’s heat loss.

• Boiler output.

• Heating hours.

• Thermostat settings.

• Hot-water consumption.

• The effectiveness of heating controls.

• Whether lower-cost off-peak electricity can be used.

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Electric heating can be expensive to operate where a property has high heat loss or requires prolonged heating throughout the day.

 

Energy Saving Trust therefore recommends considering the building, heating requirements and available electric-heating options carefully.

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Improving insulation, draught proofing and heating controls may reduce the amount of electricity required to keep the property comfortable.

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Improving Heating Controls

 

An electric boiler replacement provides an opportunity to improve the controllability of the entire heating system.

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Modern controls may include:

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• Programmable room thermostats.

• Smart thermostats.

• Individual heating zones.

• Thermostatic radiator valves.

• Separate hot-water controls.

• Time-based temperature settings.

• App-controlled heating.

• Weather-responsive controls where compatible.

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Effective controls allow heating and hot water to operate only when required, which can help reduce unnecessary energy use.

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Should You Replace an Electric Boiler With a Heat Pump?

 

A heat pump may be worth considering before committing to a like-for-like electric boiler replacement.

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Unlike an electric boiler, which creates heat directly from electricity, a heat pump uses electricity to transfer heat from the outside air or ground into the property. The suitability of a heat pump depends on the building’s heat loss, insulation, radiator sizes, external space and available budget.

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A heat pump may require:

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• Larger radiators.

• Lower heating-water temperatures.

• A suitable hot-water cylinder.

• An external unit.

• Improved insulation.

• Changes to existing pipework.

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

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Government support may be available for eligible homeowners replacing an existing electric heating system with a qualifying heat pump. Eligibility and grant values should be checked before a final heating decision is made.

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An electric boiler may remain the more practical solution where space is restricted, installation simplicity is important or a heat pump cannot be accommodated.

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Electric Boiler Replacement Costs

 

The cost of replacing an electric boiler will depend on more than the price of the appliance.

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A quotation should identify:

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• The make, model and output of the proposed boiler.

• Removal of the existing appliance.

• Electrical-circuit requirements.

• Consumer-unit alterations.

• Changes to heating pipework.

• New pumps, valves or expansion equipment.

• Hot-water cylinder work.

• System cleaning and treatment.

• Heating-control upgrades.

• Commissioning and certification.

• Manufacturer warranty arrangements.

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A straightforward replacement using an existing suitable electrical supply and heating system will normally cost less than an installation requiring major electrical or plumbing alterations.

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Homeowners should compare quotations carefully and ensure that each contractor is pricing the same specification.

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Planning Your Electric Boiler Replacement

 

A professional installer should assess both the electrical installation and the heating system before recommending a replacement.

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The survey should confirm:

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• The required boiler output.

• Whether the electrical supply is adequate.

• Whether existing radiators can be retained.

• How domestic hot water will be provided.

• Whether the boiler location is suitable.

• What controls are recommended.

• Whether any Building Regulations notification or certification is required.

• Whether a heat pump or another heating system should also be considered.

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Building Regulations contain energy-efficiency requirements for heating installations, while electrical work must comply with the applicable wiring and safety standards.

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Find an Electric Boiler Installer Through APN Boilers

 

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

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Whether your existing appliance has failed, your heating requirements have changed or you are considering switching from gas or oil, the system should be properly assessed before a new boiler is selected.

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Tell APN Boilers about your property, existing heating arrangement and hot-water requirements. We will help you find an appropriate professional for your electric boiler replacement or installation.

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