Heat Pumps vs Biomass Boilers: Which Is Better for Your Property?

Last Updated on June 27, 2025

As more UK homeowners, landlords, and commercial property owners shift to renewable heating systems, the debate of heat pumps vs biomass boilers has become increasingly relevant. 

With rising energy costs, sustainability targets, and government-backed incentives like the Boiler Upgrade Scheme (BUS), making the right choice matters more than ever.

In this guide, we focus specifically on air source heat pumps vs biomass boilers, breaking down how they compare in terms of cost, efficiency, carbon emissions, and more, helping you make an informed decision for your property.

Heat Pumps vs Biomass Boilers: A Quick Comparison

Here’s a side-by-side comparison of key factors to help you quickly understand the practical differences between these two low-carbon heating options.

Air Source Heat Pumps vs Biomass Boilers: How Do They Work?

Understanding how each system operates can help clarify which is best suited to your property’s needs.

Air Source Heat Pumps 

Air source heat pumps extract thermal energy from the outside air even in sub-zero temperatures and use electricity to compress and transfer this heat into your home’s central heating and hot water system. 

The technology operates much like a refrigerator in reverse and can deliver up to four times more energy than it consumes. Next, we’ll briefly talk about the pros and cons of air source heat pumps.

Biomass Boilers 

Biomass boilers burn organic materials like wood pellets, logs, or chips to produce heat. This combustion process heats water in a central system for space heating and domestic hot water. 

While considered renewable, their sustainability depends on sourcing practices and emissions from fuel burning. Below, we have listed the pros and cons of biomass boilers.

Heat Pumps vs Biomass Boilers: Key Differences

Now that you’ve seen the high-level differences, let’s dive deeper into each factor that influences the choice between these two systems.

Energy Efficiency

Air source heat pumps lead in terms of energy efficiency, achieving a Coefficient of Performance (COP) between 3.0 and 4.0. This means they produce 3–4 units of heat for every unit of electricity used.

Biomass boilers on the other hand, are limited by combustion efficiency and usually range between 70–90% efficiency. 

Winner: Air Source Heat Pumps
With a COP of up to 4.0, air source heat pumps clearly outperform biomass boilers in terms of efficiency. 

You get more heat output per unit of energy consumed, which translates to lower long-term running costs and reduced environmental impact especially when paired with green electricity.

What Are the Installation and Running Costs?

Installation Costs

• Air source heat pumps: £7,000–£14,000
  
• Biomass boilers: £10,000–£20,000

Both are eligible for up to £7,500 from the Boiler Upgrade Scheme, but installation costs are typically lower for heat pumps.

Running Costs

Air source heat pumps use electricity to operate, and while electricity rates can vary (typically between 25p–30p per kWh as of 2025), their high efficiency (COP of 3.0–4.0) means they deliver 3–4 units of heat for every unit of electricity consumed. 

This makes them a cost-effective heating solution when properly installed in a well-insulated home. For a more granular breakdown of energy expenses, see our post on heat pump running costs.

• Estimated annual cost: £900 – £1,300 for a typical 3-bedroom home
  
• Average cost per kWh of useful heat: ~11–13p
  
• Maintenance costs: Around £150–£250 annually for servicing
  

Biomass boilers burn wood pellets, logs, or chips, fuels that are often cheaper per kWh than electricity. However, these systems require more manual input, fuel deliveries, and regular maintenance, which can add to overall running costs.

• Estimated annual cost: £700 – £1,100 for a typical 3-bedroom home
  
• Average cost per kWh of heat: ~5–7p
  
• Maintenance & servicing costs: £300–£500 annually (including flue cleaning, ash removal, etc.)

Winner: Air Source Heat Pumps
Despite biomass having slightly lower fuel costs, the overall affordability, grant accessibility, and lower lifetime maintenance requirements make air source heat pumps the more cost-effective and predictable investment for most UK households, particularly when aiming for long-term savings and hassle-free heating.

Maintenance & Servicing

Air source heat pumps are straightforward when it comes to upkeep. They require an annual service to check refrigerant levels, electrical connections, and system efficiency. Outside of this, they require virtually no user intervention on a day-to-day basis.

Biomass boilers, in contrast, require a more hands-on approach. Users must regularly empty ash, clean combustion chambers and flue pipes, and monitor fuel quality. 

In addition to this, professional servicing is required annually to maintain efficiency and ensure safe operation.

Winner: Air Source Heat Pumps
They demand far less effort from the homeowner and are cheaper to service over the system’s lifetime.

Lifespan of Each System

Heat pumps typically last 15–20 years when serviced annually and maintained according to manufacturer guidelines. Their components such as compressors and fans are durable, and with fewer moving parts compared to combustion systems, there’s less wear and tear over time.

Biomass boilers can operate for 20–25 years, but their longevity depends heavily on consistent, thorough maintenance. 

Regular servicing includes not only standard checks but also more intensive tasks like heat exchanger cleaning, flue inspections, and component replacements due to higher operating temperatures and residue build-up.

Winner: Biomass Boilers
While they demand more upkeep, biomass boilers have a longer potential lifespan when properly maintained, making them the longer-lasting option in terms of raw years.

Which Is More Environmentally Friendly?

• Air source heat pumps produce virtually no on-site emissions and become even greener when powered by renewable electricity.
  
• Biomass boilers can be carbon-neutral, but only if the biomass fuel is sourced sustainably and emissions are well managed.

Winner: Air Source Heat Pumps
They are generally the more eco-friendly and future-proof option under the UK’s Net Zero goals.

Fuel Supply 

Air source heat pumps are powered by electricity making them incredibly convenient and low-maintenance when it comes to fuel supply. Once installed, they run continuously without the need for manual refuelling or storage. 

If your home uses a renewable energy tariff or solar PV panels, the system can run almost entirely carbon-free.

Biomass boilers, on the other hand, require a consistent supply of solid fuel—typically wood pellets, logs, or chips. This means you’ll need to manage regular fuel deliveries and ensure secure, dry on-site storage. 

While some pellet systems offer automatic feeding from a hopper, others require manual loading, especially in smaller or domestic setups.

Winner: Air Source Heat Pumps
Their fully automated operation and lack of fuel handling make them significantly more convenient and service-friendly in terms of fuel supply.

Space Requirements

Air source heat pumps require relatively little space. The external unit, usually installed outside a wall or in a garden, is roughly the size of a washing machine. 

Indoors, you’ll need space for a hot water cylinder, but this can often fit into a cupboard or airing space. Overall, they’re ideal for homes with limited internal room.

Our resource on how much space an air source heat pump needs provides helpful guidance.

Many homeowners also ask, do heat pumps need a water tank? The answer depends on your heating setup and hot water demands.

Biomass boilers are far more demanding in terms of space. You’ll need room for:

• The boiler itself (often the size of a fridge freezer or larger),
  
• A hot water cylinder,
  
• Fuel storage (bags of pellets or stacks of logs), and
  
• A flue or chimney system for exhaust.

This makes biomass boilers more suitable for larger properties, farms, or outbuildings where indoor and outdoor space is not an issue.

Do You Need Planning Permission?

In most cases, air source heat pumps fall under permitted development rights in the UK, meaning you don’t need planning permission as long as the installation meets specific criteria (e.g., noise limits, size, and distance from boundaries). 

However, listed buildings or properties in conservation areas may require consent.

Biomass boilers may require planning permission, particularly if you need to install a new flue, store fuel externally, or if you live in an urban area. Smoke control regulations may also apply, depending on the type of biomass fuel and your local council’s environmental policies.

Winner: Air Source Heat Pumps
Their simpler regulatory pathway and lack of combustion-related servicing requirements make them more straightforward to install and maintain in most settings.

Noisy Levels

Air source heat pumps are relatively quiet. Most operate between 40–60 decibels, comparable to a modern dishwasher or refrigerator. 

While you might hear a gentle humming or fan noise from the outdoor unit, it’s unlikely to be intrusive and often goes unnoticed, especially when installed properly. Our post on how noisy an air source heat pump is outlines what to expect.

Biomass boilers, in contrast, can be noisier due to the sound of combustion, pellet feeding mechanisms, and ventilation systems. 

These sounds can be more disruptive, particularly if the system is housed indoors or near living areas. Acoustic insulation can help, but it’s still something to consider for residential properties.

Winner: Air Source Heat Pumps
Their quieter operation and more stable noise profile, even with minimal servicing, make them the preferable option for noise-sensitive households.

Are Heat Pumps and Biomass Boilers Suitable for All Property Types?

Air source heat pumps

Air source heat pumps are highly adaptable and work best in well-insulated homes where heat loss is minimised. Their compact design and minimal on-site infrastructure make them suitable for urban, suburban, and rural settings alike.

That said, they can still perform effectively in older properties if proper retrofit measures like double glazing, wall and loft insulation are in place. 

Our article on how air source heat pumps work in old houses explains how they can still be a great option with the right upgrades.

If you’re not sure whether your home is compatible, read our guide to determine if your house is suitable for a heat pump to understand what property types work best.

Biomass boilers

Biomass boilers, with their high heat output, are a solid choice for larger, poorly insulated, or rural properties where heating demand is high. 

They’re more flexible when insulation standards are lower, and they can heat properties that would be challenging for a heat pump alone. 

However, they come with significant space requirements and servicing demands, including regular fuel system checks, ash removal, and flue cleaning, factors that may limit their practicality in smaller homes or urban environments.

Winner: Air Source Heat Pumps
Their flexibility, compact footprint, and low-maintenance suitability across a wide range of property types make them the more versatile solution overall.

Should You Choose an Air Source Heat Pump or a Biomass Boiler?

If you’re a UK homeowner or landlord looking for:

• Low maintenance
  
• High energy efficiency
  
• Cleaner energy
  
• A future-proof heating solution that aligns with the UK’s decarbonisation goals

…then an air source heat pump is the clear winner in most scenarios, especially when paired with proper insulation.

Biomass may be suitable for specific rural properties with space and easy access to affordable fuel, but for most modern homes, heat pumps provide better long-term value, performance, and environmental benefits.

If you’re curious about how heat pumps stack up against other boilers and heating and cooling systems, read our other helpful guides:

Hydrogen boilers vs heat pumps 

Heat pumps vs gas boilers

Air source heat pumps vs oil boilers

Air source heat pumps vs air conditioners

Electric radiators vs air source heat pumps

Ready to Upgrade Your Heating? Get a Free Air Source Heat Pump Quote

Switching to a low-carbon heating system doesn’t have to be complex. At Eco Happy, we make the transition seamless with expert guidance, MCS-certified installers, and access to Boiler Upgrade Scheme funding.

Take the first step towards greener, cheaper heating.

Request your free air source heat pump quote today!

Our team will assess your property and help you decide whether an air source heat pump is right for you.