ASHP heating, or Air Source Heat Pump, is an innovative and renewable heating system. It pulls some heat out of the cold air around us to effectively heat our homes and water.
We’ve seen firsthand how these systems work not just adequately, but optimally in conditions down to -15°C. They transform cold outside air into tremendously valuable heat energy with exceptional efficiency.
The reduced carbon emissions compared to existing gas boilers make our customers happy, as does the prospect of saving money on their energy bills. ASHPs should be used in conjunction with underfloor heating or radiators sized appropriately to their lower output for ultimate comfort.
Understanding Air Source Heat Pumps
Air source heat pumps (ASHPs) have quickly become the key technology of choice in the UK’s drive to electrify its heating. These residential heat pump systems revolutionize how homes maintain warmth while significantly reducing their carbon footprints. Unlike conventional heating methods that burn fuel, an air source heat pump works by transferring heat from the outside air into your home, even in cold conditions.
1. Basic Principles and Operation
At a very basic level, ASHPs work on a relatively straightforward thermodynamic principle. Similar to a refrigerator in reverse, they pull heat out of the ambient outdoor air and concentrate it for heating indoor spaces. The system operates essentially the same way a refrigerator does, but in reverse.
Even at a bone-chilling -15°C, these units still perform pretty darn good at extracting useful heat out of the air. They’ve proven themselves in extreme cold weather! The single refrigerant circulates through the entire system, absorbing heat from the outside. Then, a compressor increases the temperature of that heat by compressing it, and the heat is distributed throughout your home.
2. Types of Air Source Heat Pumps
We offer two main types of ASHPs: air-to-air and air-to-water systems. Air-to-air pumps circulate warm air directly into your home through fan coil units. These are great for more open-plan designs.
Air-to-water systems simply hook up to your existing wet central heating system, pumping warm water around your traditional radiators, underfloor heating or hot water cylinders. The majority of homes in the UK use air-to-water systems since they work well with currently installed radiator infrastructure.
3. Components of an ASHP System
A typical ASHP is an assembly of four major components in tandem. The outdoor unit has the evaporator coil and fan, which pulls in outside air. Inside, you’ll find the compressor, condenser coil, and expansion valve.
The distribution system could consist of fan coils, radiators, or underfloor piping based on your arrangement. Each component works to maximize the heat exchange process, providing year-round comfort and efficiency.
4. How ASHPs Extract Heat
The refrigerant’s ability to absorb heat at very low temperatures is the primary scientific basis behind the heat extraction process. When cool outside air flows over the evaporator coil, the liquid refrigerant absorbs heat from the air and changes into a gas.
This gas then travels to the compressor where pressurizing the gas raises its temperature considerably. That now-hot gas either heats the air that circulates through your home or warms water for your heating system. Once cooled back down to a liquid state, it begins the process new again.
5. Energy Efficiency Ratings Explained
As a note, we typically measure ASHP efficiency in COP and SPF (Seasonal Performance Factor). A modern air source heat pump (ASHP) has a coefficient of performance (COP) of 3 to 4. This equates to it producing 3 to 4 units of heat per unit of electricity used.
SPF provides a better indication of year-round efficiency by factoring in seasonal temperature changes experienced in the UK. The more stars the better, meaning lower running costs and less carbon emissions for your home.
Overall, ASHPs are increasingly cost-effective, efficient and sustainable solutions for space and water heating in UK homes.
Benefits of ASHP Heating Systems
Air Source Heat Pump (ASHP) heating systems offer wonderful benefits to homeowners as a viable heating alternative. If you are considering an upgrade to your home heating solution, ASHPs are an excellent option. These systems extract warmth from the ambient air and transfer heat indoors, providing a smart, efficient replacement for conventional gas or oil burners.
Environmental Impact and Carbon Reduction
ASHPs produce substantially less carbon emissions than conventional heating systems. By tapping into renewable energy all around us in the air, we could reduce our carbon footprint by about 13% each year. This reduction is critical to fighting climate change and ensuring a healthy, more sustainable future.
These systems are all powered by electricity, removing the need to burn fossil fuels on site. This decision makes them a much cleaner choice for eco-friendly homeowners across the UK.
Lower Energy Consumption
The energy efficiency of ASHP systems is nothing short of spectacular. These units are 3 to 4 times more efficient than standard gas boilers. In reality, some models are delivering an incredible 300% efficiency!
This ensures that for each unit of electricity consumed, the system generates three units or more of heat energy. In fact, the air source heat pump tariff increases cost-effectiveness by a whopping 70%. This leads to significant energy bill savings over time for homeowners, particularly if their homes are more energy efficient.
Year-round Functionality
ASHPs perform well year-round, including in colder British winters. The systems offer dependable heating with little or no carbon emissions in winter months and can reverse their operation to bring cooling in summertime.
This two-in-one feature ensures comfort regardless of how cold or hot it gets outside. In addition to enhanced comfort, it gives you integrated hot water year-round.
Long Lifespan and Reliability
With maintenance, ASHPs can rack up lifespans of 15-20 years, if not more. This increased longevity provides tremendous value in contrast to traditional heating systems that may require replacement sooner.
Since these systems have fewer moving parts than traditional combustion-based heaters, the likelihood of breakdowns and costly repairs greatly decreases.
Government Incentives and Schemes
The UK government actively encourages the adoption of ASHPs through a number of initiatives. The Renewable Heat Incentive (RHI) scheme offers regular cash payments for the production of renewable heat with eligible technologies.
These financial incentives can significantly mitigate upfront installation expenses. They do much more, increasing the return on investment and making ASHPs an ever more attractive option for UK homeowners looking to future-proof their heating systems.
ASHP Types and Applications
We believe understanding the various types of Air Source Heat Pumps (ASHPs) is essential for making informed decisions about heating solutions for your property. Available British Technology These systems have come a long way in recent years, now offering more efficient and versatile applications for British homes and businesses.
So let’s break down the major buckets. We’ll touch on their different applications to better help you determine which is the best fit for your needs.
Air-to-Water Heat Pump Systems
Air-to-water heat pumps are one of the most common ASHP types seen on the UK market. These systems remove heat from the ambient outdoor air. They then pass that heat on to water that moves through radiators, underfloor heating systems, or provides domestic hot water.
Our experience shows that these systems succeed in high-temperature heating configurations. They are particularly well matched with underfloor heating, which needs water temperatures of 35-45°C. A typical air-to-water system is sufficient to fulfill the entire heating and hot water demand of an average three-bedroom semi-detached home in the Midlands.
When compared to conventional gas boilers, carbon emissions can be reduced by up to 60%. These systems generally obtain Coefficients of Performance (COP) from 3 to 4. This is because they produce three to four times as much heat as the electricity they use.
Air-to-Air Heat Pump Solutions
Air-to-air heat pumps exchange heat from your outside air directly into your indoor spaces. These systems operate like reverse-cycle air conditioners and deliver heated air via indoor units or ducted networks.
They do a much better job than air-based systems at conditioning open-plan areas, and as a rule, they’re cheaper to install than air-to-water systems. Our retail customers across the South of England love these for heating one room and as additional heating to existing systems.
For instance, a 60m² flat in London might use a multi-split air-to-air system with units in the living area and bedrooms, providing efficient heating during winter months and cooling during summer. That versatility means they can be great climate-control solutions any time of year, although they do not deliver hot water.
Hybrid Heat Pump Configurations
Recently, we’ve seen a lot of enthusiasm for hybrid heat pump systems across the UK. This trend is most pronounced in households that already use gas or oil boilers. These smart setups connect an ASHP with a traditional boiler.
They seamlessly toggle between energy sources, keeping the lights on while optimizing efficiency and savings in real-time. During mild weather, the heat pump handles the heating load, while the boiler takes over during extremely cold periods when heat pump efficiency might decrease.
In Yorkshire for instance, a typical 4-bed detached house would usually be assumed to have a hybrid heating system. The new system employs a heat pump 80% of the year, with the old boiler turning on only at temperatures below 0°C. This strategy offers a concrete way to move toward renewable heating. It keeps the status quo safe when demand is at its highest.
Monobloc vs Split System Options
During the preparation of an ASHP pipeline, the decision between monobloc and split ASHPs largely comes down to particular property needs. Monobloc units put all the components in one outdoor unit, making installation simpler and often less expensive.
These are especially favoured for smaller lots or where indoor space is constrained. Split systems, on the other hand, separate equipment between outdoor and indoor units, with refrigerant piping connecting the two. Although they need a more involved installation, split systems are frequently able to reach marginally higher efficiencies and provide greater flexibility in placement.
If you live in a typical Victorian terraced house in Manchester with no or small garden, assume a small, monobloc unit with a capacity rating of 8 kW. Conversely, a new, bigger country house in Norfolk could definitely use a well-placed split system that hides the visual impact but provides the performance.
In summary, the type of ASHP you choose should be guided by your property’s unique heating needs and limitations.
Installation Considerations
When installing an air source heat pump (ASHP), this requires taking into account a few important considerations. Addressing each of these factors will result in optimal performance. Whether using a remote, clustered arrangement or a more traditional configuration, a careful installation plan can both optimise efficiency and prevent expensive miscalculations while maintaining compliance with local ordinances.
Having guided hundreds of homeowners through this process, our team has learned which considerations are most critical to making a successful match.
Property Suitability Assessment
Before moving forward with an ASHP installation, we conduct a thorough assessment of your property. This evaluation helps us determine whether your home is suitable for this heating solution. We look at your current heating system, insulation levels, and overall energy efficiency.
Consider any necessary insulation upgrades, such as loft insulation, cavity wall insulation, or double glazing, to maximise the benefits of your ASHP. These improvements can significantly enhance the performance of your heat pump and reduce running costs.
Total installation costs for an air source heat pump in a new or self-build property are expected to be upwards of £11,000, but this investment often pays for itself through energy savings.
Space Requirements and Positioning
ASHPs need dedicated space both on the property and outside the property lines. The outdoor unit requires sufficient airflow around it to get enough oxygen for the cooling process. For Grant heat pumps, the clearances we’d suggest are given in the Installation and Servicing Manual.
Make sure to install the heat pump in an orientation that makes it as efficient as possible. For best results, orient it toward the warmer side of your property, ideally south-facing. Ensure that the condensate from the heat pump doesn’t run onto sidewalks or roadways.
Then come winter, it would freeze and create a treacherous sheet of ice.
Planning Permission Guidelines
Though most ASHP installations are exempt from needing planning permission, it’s always good practice to check local regulations and think about limitations. What’s more, the regulations differ based on where you’re located, what type of property you have, and if you live in a conservation zone or not.
We guide our clients through these mandates to maintain compliance with the latest building codes and standards.
Choosing a Qualified Installer
The first key step in an air source heat pump installation is finding the best heat pump installers to fit your new air source heat pump. Thousands of installations and dozens of successful case studies later, the air source heat pump track record continues to build itself with each passing year.
So take your time and choose the best professionals to help ensure a successful installation. The right installer will make sure your whole system is properly sized, installed for optimum efficiency, and adequately commissioned.
Routine maintenance checkups are a sure way to increase the life of your ASHP. They’ll better equip you to efficiently nip any potential problems in the bud as well.
Taking everything into account, with thoughtful planning you can get the best performance and lifespan out of your ASHP.
Cost Analysis and Financial Planning
We know switching out your old system for a new heating system, like a residential heat pump, is no small financial decision. The case for air source heat pumps (ASHPs) requires a big up-front commitment, but their long-term energy savings generally outweigh these initial expenditures.
Initial Investment Requirements
Installation of an ASHP system usually involves a capital outlay above that of conventional heating systems.
Cost of installing a heat pump for an average UK home range widely from £7,000 to £13,000 depending on property size and system specifications. That price covers the unit itself, installation labour, and any modifications required to your current heating setup.
This price might seem like a lot when looking at a typical boiler. Don’t forget the lifespan and efficiency benefits, which will net you significant savings over time.
Running Cost Expectations
Our research shows that families are saving more than 50% on their running costs. It’s cheaper to switch to a heat pump than run a gas boiler. This is now commonly achievable.
The average annual standing charge is now £116. In addition to that, the annual electricity cost for heating and hot water is an average of £778 per year. These figures are encouraging when compared to gas systems over the long term.
As energy prices are increasingly volatile and a carbon tax is implemented, benefits become even more apparent.
Maintenance Expenses
Properly maintaining a facility is critical to maximizing performance, safety, and asset life.
A professional service is advised annually, which usually costs £150 to £300. This is similar to gas boiler annual service – but is much better value given the heat pump’s longer asset life.
To help your outdoor unit operate at peak efficiency, you should routinely remove any debris that builds up around the unit. Furthermore, look for proper airflow to prevent unnecessary service calls.
Return on Investment Timeline
Heat pumps can last 15 to 20 years with the right kind of maintenance. They typically outlive conventional heating systems.
Depending on the circumstances, an ASHP will typically operate with an efficiency of at least 2.5 to 3.5. In comparison, new A-rated gas boilers have a minimum efficiency of 92%, though they never achieve anywhere near that in reality.
This difference in efficiency translates to massive savings over the life of the system. Homeowners still have a positive return on investment in under 7 to 10 years.
Available Funding and Grants
The UK government has provided a range of financial incentives to encourage the uptake of ASHPs. In the UK, the Boiler Upgrade Scheme gives out grants of up to £5,000 to local homeowners to offset installation costs.
Local councils often have extra help available, and some energy companies have special tariffs for heat pump owners. As always, verify the eligibility requirements directly using government resources, like Grants.gov and SAM.gov.
Work with qualified installers to help navigate the application process. Overall, ASHPs provide significant long-term savings even with increased initial investment.
Integration with Existing Systems
When upgrading to air source heat pump (ASHP) heating, we understand that integrating with your current setup is a primary concern. Our experience shows that most existing systems can work alongside ASHPs, though some modifications may be necessary to achieve optimal performance.
Whether or not they are a compatible fit depends on what heating infrastructure you currently have and what your property’s specific needs are.
Compatibility with Radiators
While most existing radiators can be compatible with ASHP systems, there are several key factors to keep in mind. Traditional radiators designed for gas or oil boilers typically operate at temperatures between 60-80°C, whilst ASHPs work most efficiently at lower temperatures (35-55°C).
In our experience, bigger radiators or high-pressure, fan-assisted models tend to make up for this shortcoming. In a recent project in Manchester, we replaced standard radiators with oversized models, increasing the surface area by 30% without taking up more wall space. This maintained comfortable room temperatures even at lower water temperatures.
Underfloor Heating Considerations
For another, underfloor heating works brilliantly with ASHPs because both technologies run efficiently at lower temperatures. For residential buildings with underfloor heating already in place, the switch can be made with minimal hassle and disruption.
This even distribution provides comfortable radiant heat and helps maintain a consistent temperature throughout the space. We have retrofitted ASHPs in dozens of properties across the UK. Property owners who kept their underfloor systems noticed an increase in energy efficiency.
With more advanced systems, such as double-joist underfloor systems, we may recommend a diagnostic inspection of pipe spacing and floor insulation to help ensure evenly spread heat.
Hot Water Cylinder Requirements
Your current hot water cylinder probably requires replacement when installing an ASHP. Standard cylinders are not made to withstand the reduced operating temperatures of heat pumps.
For new builds, we suggest always installing a suitably sized heat pump specific cylinder, with a greater coil surface area and improved insulation. These integrated hot water storage cylinders make absolutely sure that you can enjoy more than enough hot water even with the lower flow temperatures from the heat pump.
Smart Controls and Optimisation
New smart controls can dramatically improve ASHP performance. These systems automatically learn your heating schedule and adapt to save energy when you aren’t home using smart technology.
Weather compensation technology—in which the system is adjusted depending on outdoor temperatures—pairs especially well with heat pumps. Our clients in Edinburgh reduced their heating costs by 15% after adding smart controls that allowed zone-by-zone temperature management through a simple app interface.
Performance Across UK Climate Conditions
We’ve thoroughly tested our air source heat pump systems (ASHPs) across diverse British weather patterns to ensure they deliver reliable heating and cooling for UK homes. Our systems, including the standard air source heat pump, are specifically engineered to handle the unique challenges of our maritime climate.
Winter Efficiency Factors
In winter, we see our ASHPs perform really well even at sub-zero temperatures. Even at -3°C, our baseline models get a very strong 2.5 COP (Coefficient of Performance). This is because for each unit of electricity they use, they create 2.5 units of heat!
We’ve made advances on many of our newer models that include new defrost cycles that minimize troubleshooting in these frosty conditions. The addition of weather compensation controls allows our systems to anticipate temperature drops, adjusting output accordingly to maintain comfort while optimising energy use.
In especially exposed regions, our added resistance heaters turn on only when necessary. This keeps you warm while helping to reduce overall electricity use in Virginia.
Summer Cooling Capabilities
Our reversible ASHPs offer highly responsive cooling to help counter the impact of hotter, longer British summers. The systems act as a gentle yet consistent form of cooling. They are able to maintain healthy indoor temperatures around 18-22°C without the negative impacts associated with traditional air conditioning.
In cooling mode, a typical UK three-bedroom semi-detached home is around 0.8 to 1.2kW. This represents tremendous savings from traditional cooling systems. The slow temperature drop avoids the jarring cold spots experienced with more rudimentary forms of cooling.
Regional Performance Variations
We have been busily mapping this performance data across major climate zones within the UK to help set realistic expectations. Operating in mild, southern coastal climates yields 10-15% more efficiency in our systems than in climates like northern Scotland.
In Wales and the wetter, rainy west, where climate models predict increasing precipitation, our humidity-optimized models halt efficiency degradation under wet weather. Urban installations perform exceptionally well due to the heat island effect. They are frequently 5-8% more efficient than rural locations with the same type of facilities.
Weather-Dependent Considerations
In reality, heavy rainfall makes our ASHPs more efficient by cleaning the external unit’s heat exchanger while it’s running, preventing debris build-up and keeping performance high. For extended dry weather, our dust-resistant coatings protect performance degradation.
Particularly wind exposure can greatly affect performance. This is why we suggest implementing strategic positioning or basic wind breaks for systems located in very exposed environments. Our smart controls automatically and continuously recalibrate using years of historic and real-time weather data, predicting what’s coming before it even arrives—so you’re always in perfect comfort.
In summary, our ASHPs provide dependable performance throughout all UK climate conditions.
Maintenance and Longevity
Regular maintenance is key to getting the most out of your ASHP system! We fully appreciate the need to maintain it in tip top condition. With consistent maintenance, you can ensure everything is working at peak performance while increasing your valuable asset’s lifespan by years.
With the proper maintenance and attention, an ASHP can provide comfortable, efficient service to your home for 15-20 years – or more.
Routine Service Requirements
From our own experience, we have found that ASHP systems need less maintenance than conventional heating systems, though they still require regular upkeep. We suggest getting a professional check-up each year, preferably in advance of the heating season.
Common tasks on these service visits might involve checking/recharging refrigerant levels, cleaning coils and filters, inspecting electrical connections, and making sure airflow is adequate. Lack of maintenance between professional visits, regular monthly filter cleaning or replacement is necessary to keep the unit running efficiently.
Especially in the fall, keeping leaves and debris from piling up on the outdoor unit ensures airflow isn’t restricted, which can harm performance.
Troubleshooting Common Issues
As we get deeper into the troubleshooting side of ASHP systems, you may notice most issues can be solved without the need for an expensive service call. If you find your system is not heating effectively, start by ensuring that the thermostat is set to the desired temperature.
Second, check that circuit breakers have not tripped. Inadequate airflow is usually a sign of dirty filters or obstructed vents, things you can address with a quick fix. Strange sounds could be an indication of loose parts or foreign objects in the outside unit.
For icing issues, most modern units have automatic defrost cycles, but persistent ice formation may indicate a refrigerant leak or airflow problem requiring professional attention.
Extending System Lifespan
Here are a few key takeaways we learned to help ensure your ASHP enjoys a long, productive life. An easy way to help your system work more efficiently is to install proper insulation throughout your home.
Regularly ensuring the outdoor unit remains dirt and vegetation free, making sure to keep at least 24 inches of clearance, avoids the risk of overworking. Maintaining moderate temperatures instead of making extreme changes often results in less stress on equipment.
By using a programmable thermostat to automatically operate it less when you’re away from home, you further prolong component life while saving energy.
Professional vs DIY Maintenance
We support the economy that comes with private sector professional service mixed with long-term, manageable homeowner maintenance. DIYers, you’re up to the challenge!
First, clean or replace filters, remove debris from around the outdoor unit, make sure the thermostat is set correctly, and vents aren’t blocked. While refrigerant handling, electrical component inspection and internal system checks must be handled by qualified engineers, certified professionals should be provided.
Some problems are easily caught with regular homeowner observation, but a trained professional makes sure installations are safe and up to code, keeping you protected under manufacturer warranties.
Consistent care maximises ASHP efficiency and lifespan.
Why Choose Greentech Renewables
At Greentech Renewables, we’ve proudly established our solid reputation on providing heating efficiencies that are reliable, efficient and most importantly sustainable—all throughout the UK. Our crew has spent the last six years installing air source heat pumps (ASHP).
We empower families to lower their climate impact and experience a new level of comfort and warmth all year long.
Expertise and Certification
We hire fully qualified engineers, all of whom have all necessary MCS (Micro-generation Certification Scheme) certifications to undertake ASHP installations. Our in-house team has been trained and continues to be trained on the most recent technological innovations and installation practices.
This level of expertise ensures that we are able to work on properties of all sizes and types, from simple terraced houses right through to large, complex detached homes. Our field engineers personally visit your facility and conduct extensive walk-through evaluations.
To achieve maximum comfort and efficiency in our British climate, it’s vital to always install the right size heat pump in the right place.
Comprehensive Service Package
Our service extends beyond simply fitting a heat pump. We offer a complete package that includes initial home assessment, system design, installation, and commissioning.
During the assessment phase, we evaluate your current heating setup, insulation levels, and specific requirements. We take measurements of your living space and calculate heat loss to recommend the right capacity system, typically between 5kW for smaller properties and 16kW for larger homes.
Our team handles all paperwork for government incentive schemes, making the transition to renewable heating straightforward.
Customer Satisfaction Record
The proof is evident in our 4.8-star average rating from more than 500 customer reviews. We have a track record of having installed over 1000 ASHP installations throughout the UK.
Our strong presence is particularly recognized in Scotland, Wales and Northern England, where heating efficiency has been a priority. Our customers consistently praise our clear communication, punctuality and the performance of their heating systems, with many reporting energy bill reductions of 30-50% compared to their previous fossil fuel systems.
After-Sales Support and Warranty
We back our installations with industry-leading warranty coverage, and unparalleled after-sales support gives you peace of mind. All our ASHP systems include manufacturer warranties ranging from 5 to 7 years.
Our installation workmanship is guaranteed for 2 years. Our passionate support team is available to assist you six days a week. We’re always ready to address any questions or concerns that may arise post-installation!
For starters, we protect ASHP value with best-in-class experience and training. We bring ASHP solutions you can count on.
Frequently Asked Questions
How do air source heat pumps work in the UK climate?
Air source heat pumps (ASHPs) can pull heat from ambient air even with outside temperatures as low as -15°C. Combined with the UK’s temperate climate, these residential heat pumps perform superbly, outputting consistent home heating year-round. All new heat pump system designs are purpose-built for the UK climate, ensuring they operate effectively in typical Brit weather.
What savings can I expect on my energy bills with an ASHP?
On average, UK householders save upwards of 30-50% on their heating bills compared to conventional gas boilers. Your potential savings will vary based on what heating system you currently use, such as a residential heat pump or a standard air source heat pump, how well your home is insulated, and your heating habits. The most favorable financial returns will come from using an efficiently installed heat pump system in a well-insulated home.
Do I need planning permission to install an air source heat pump?
Due to the nature of air source heat pump installations, most in the UK are considered to be permitted development and don’t need planning permission. While many heat pump controls are not subject to planning permission, works on listed buildings, conservation areas, and some quirky structures might require it. Therefore, before you get started, we advise contacting your local council to see what’s allowed and what isn’t.
Can an ASHP replace my existing boiler completely?
To put it simply, yes, an air source heat pump (ASHP) can completely replace your current gas boiler for both heat and hot water needs. This viable heating alternative works beautifully with larger radiators and underfloor heating systems. For optimal energy savings, we suggest pairing our service with insulation upgrades in your home.
Are there any government grants available for ASHP installation?
Currently, the Boiler Upgrade Scheme provides £7,500 of grant funding toward air source heat pump installation costs for eligible properties in England and Wales. Council area-specific schemes, such as the Home Energy Scotland Loan, might be available depending on where you live. Our expert team will work to identify the grants that you are eligible for and best suited to your home heating needs.
How long does an air source heat pump typically last?
A higher-quality air source heat pump (ASHP) system averages 15-20 years with proper ongoing heat pump maintenance, while conventional boilers typically last closer to 10-15 years. Sometimes, the outdoor heat exchanger unit needs replacement first, though internal components often outlast that. Without annual servicing, these heating options die much younger than their lifespan suggests.
