Air Source Heat Pumps

OHM Energy Sussex

What Are Air Source Heat Pumps?

Air source heat pumps (ASHPs) are an innovative and sustainable heating technology that works somewhat like a refrigerator but in reverse. Where a refrigerator works by removing heat from inside itself, an air source heat pump takes heat from the outside air and upgrades it to heat homes and hot water, even when temperatures are as low as -25°C. This technology suits Sussex’s climate, offering an energy-efficient solution to heating needs throughout the year.

Air-source heat pumps are often considered brand-new technology, but any home with a refrigerator already utilises a similar mechanism, as both systems are essentially heat pumps. Thus, ASHPs are a familiar technology in a new application.

OHM Energy

At OHM Energy, we install Mitsubishi Electric Ecodan Air Source Heat Pumps, not just because they’re top-notch for tackling variable Sussex weather but because they really make sense for your home. Ecodan products are actually designed for UK conditions and built in Mitsubishi Electric’s factory in Sterling, Scotland.

They’re quiet, easy to manage, and kind to your wallet and the planet over time. If you’re thinking about making your home warmer and more eco-friendly, Ecodan is a choice you can feel good about.

  1. High Efficiency and Sustainability: Ecodan heat pumps are recognised for their high efficiency, converting every 1kW of electrical energy into 3kW of heat energy. This efficiency is cost-effective and environmentally friendly, as it significantly lowers CO2 emissions compared to traditional heating methods.
  2. Designed for UK Climate: These pumps are specifically engineered for the UK’s weather conditions, ensuring optimal performance even in the chilly Sussex winters, with operational capacity at temperatures as low as -25 degrees Celsius​.
  3. Versatility and Compatibility: Ecodan systems are versatile, fitting various property sizes and types, from apartments to large detached houses, and even small commercial properties. They can replace existing heating systems or complement them in a hybrid setup, and are compatible with both underfloor heating and traditional radiators.
  4. Low Maintenance and Durability: Ecodan systems require minimal maintenance and are known for their durability, often lasting 15 to 20 years with proper service and maintenance.
  5. Quiet Operation: The units operate quietly, making them suitable for residential areas where noise might be a concern. Ecodan models are even designed to meet stringent planning permission requirements regarding noise levels.
  6. Advanced Monitoring: Each unit comes with advanced energy monitoring capabilities, allowing homeowners and housing associations to track energy consumption accurately. This feature is beneficial for managing costs and ensuring efficient energy use.

What makes Sussex such a great location for Air Source Heat Pumps?

Sussex is particularly well-suited for adopting air source heat pump (ASHP) technology, thanks to its climate, the characteristics of its rural areas, and the potential to integrate with solar power.



Sussex enjoys a temperate climate with mild winters compared to many other regions in the UK. This is advantageous for ASHPs, which take latent heat from environmental air. The mild temperatures in Sussex ensure that ASHPs are cost effective further benefitting the homeowner.

Rural Areas with Oil Dependency

Rural Areas with Oil Dependency

A significant portion of Sussex is rural and not connected to the national gas grid, which means that many residents are forced to rely on oil for heating. This reliance is getting increasingly costly, not to mention being bad for the environment. ASHPs provide a sustainable alternative, offering rural homeowners a more environmentally friendly heating solution that reduces carbon emissions. And you’ll no longer have to have an oil delivery every 6 months!

Solar Integration Potential

Solar Integration Potential

Depending on who you talk to, Eastbourne, Hastings and Bognor Regis all claim to be the sunniest place in the UK. As far as we’re concerned though, it’s important to note that they’re all in either East or West Sussex.

Sussex is an ideal location for integrating solar panels with heat pumps. This combination allows homeowners to use solar-generated electricity to power their ASHPs, further reducing their energy costs and enhancing the sustainability of their homes. The synergy between solar panels and ASHPs maximises the use of renewable energy sources, making it a compelling option for those looking to reduce their environmental impact and achieve greater energy self-sufficiency.

All These factors make our part of the world an optimal region for the deployment of ASHP technology, supporting the transition to more sustainable energy solutions while addressing the specific needs and opportunities presented by the local environment.


Switching to an air source heat pump like the Ecodan not only means enjoying the warmth of your home in a more energy-efficient and environmentally friendly way, but also offers significant cost savings. These systems are designed to use less energy while maintaining high comfort levels, which is great for the planet and your wallet. Unlike traditional heating methods that rely on oil or gas, running a heat pump typically results in lower monthly bills. This shift can reduce your worry about the fluctuating costs of fossil fuels, making it an economically wise choice for homeowners in Sussex.

Plus, there’s more good news on the financial side from the government as well. The Boiler Upgrade Scheme (BUS) offers grants to help homeowners in England and Wales make the switch to greener heating systems like air source heat pumps. This initiative can significantly offset the upfront installation cost, making it an even more attractive option for those considering an eco-friendly upgrade.

These factors make air source heat pumps a compelling choice for homeowners in Sussex looking to boost their home’s efficiency and comfort while keeping an eye on their budget and the environment. For more details on the Boiler Upgrade Scheme (BUS) and to check your availability, you can visit the official UK government website.

Installation Process

Installing an air source heat pump (ASHP) in Sussex, or anywhere for that matter, is a process that OHM Energy handles with exceptional care and expertise. Here’s how we ensure your new heating system meets your needs perfectly, from the initial survey to final instructions on how to get the best out of your ASHP.

1. Let's jump on a call

In a quick call we can usually learn enough about your property to give you an indication of what is required and approximate install cost. Use this link to book a call with our team.

2. Initial Home Survey

The first step in the installation process is conducting a thorough survey of your home. OHM Energy takes this step seriously because it’s crucial to determine the right size and specification of the heat pump for your home. We’ll look at the size of your radiators, and the internal volume of your rooms. Where necessary we’ll recommend upgrades to ensure that the system we install perfectly matches your home’s heating needs and architectural specification.

3. Choosing the Right System

Based on the survey, we’ll design a bespoke system to your requirements and then provide you with a formal quote for review. We select an Ecodan ASHP system that suits your property’s physical layout and heating requirements. We consider factors like home insulation, existing heating systems, and your personal heating preferences.

4. Installation

Upon acceptance of the quote, the installation process can begin.

This includes:

  • Setting up the outdoor unit, which usually sits discreetly outside your home.
  • Integrating the indoor unit with your home’s existing heating infrastructure, be it underfloor heating or radiators. Whilst every effort is made to ensure that the process is as smooth as possible, for obvious reasons we cannot take responsibility for your homes existing heating systems.
  • Ensuring all electrical and plumbing connections are made safely and efficiently.
  • The average install usually takes around a week, with your hot water off for just one day.
5. Commissioning and Handover

We don’t just leave you to figure things out independently after installation. We commission your new system, ensuring it operates efficiently and in line with all safety standards. We also train you on how to use your Air Source Heat Pump effectively. Unlike competitors who might not fully explain the nuances, we ensure you understand that ASHPs operate differently from traditional gas heating systems. They are designed to provide continuous background heating, which is more efficient at lower flow temperatures. This method helps maintain a consistent and comfortable temperature throughout your home.

6. Ongoing Support and Education

We believe in empowering our customers with knowledge about using their new system efficiently. It’s important to understand that ASHPs should not be turned on and off like traditional boilers. Instead, they work best when maintained at a steady temperature, enhancing comfort and energy efficiency.

By choosing OHM Energy for your ASHP installation, you’re opting for a service that ensures you are informed and comfortable with your new system. This will pave the way for long-term satisfaction and efficiency in your home heating.

OHM Energy

Get a heat pump quote

Use our new estimate tool to get information on your property that will help us quote the size of Heat Pump needed to heat your home effectively and efficiently. The tool will also allow us to see the most up to date EPC rating for your property and whether or not your are likely to be eligible for the Boiler Upgrade Scheme grant of £7,500.

Use our Spruce tool to get an estimate in just a few minutes.


Maintenance & Care

As with any heating system, maintaining and caring for your air source heat pump is key to ensuring it operates efficiently and reliably over its lifespan. At OHM Energy, we focus on the initial installation and comprehensive aftercare to help our clients keep their systems in top condition.

Service and Maintenance

OHM Energy offers tailored service and maintenance plans that are designed to keep your heat pump system functioning optimally. These plans can help prevent unexpected breakdowns and extend the life of your equipment.

By focusing on preventive maintenance and being proactive about potential issues, homeowners can enjoy the full benefits of their ASHP with minimal disruptions. OHM Energy’s commitment to aftercare ensures that you have expert support available when you need it, helping you maximise your heating system’s efficiency and longevity.

Regular Maintenance Checks

OHM Energy recommends regular maintenance checks to ensure your ASHP runs efficiently. These checks typically involve inspecting and cleaning filters, fans, and coils to prevent airflow blockages or efficiency losses. It’s also important to check the refrigerant levels and ensure there are no leaks.

Seasonal Inspections

Before the heating season begins, a more thorough inspection should be carried out. This includes checking the system’s antifreeze levels, ensuring that all electrical connections are secure, and checking that the outdoor unit is free from leaves, dirt, and debris that can accumulate and hinder performance.

Client Check-Ins

OHM Energy prides itself on regular client check-ins to address any concerns and provide ongoing support. We understand that many homeowners may not be familiar with the nuances of maintaining an ASHP, so we make ourselves available to guide you through the process.

Troubleshooting Common Issues

  • System Not Heating Adequately: This could be due to incorrect thermostat settings, a blocked filter, or a more complex issue like a refrigerant leak. Checking the thermostat and cleaning the filter are good first steps, but if the problem persists, professional service may be needed.
  • Strange Noises: Any unusual noises from the ASHP could indicate a mechanical problem, such as loose parts or blockages within the system. It’s advisable to turn off the system and call for professional help.
  • Ice Build-Up: During very cold weather, it’s normal for the outdoor unit to have frost, but excessive ice build-up can be a sign of malfunctioning defrost cycles. If the system’s automatic defrost function does not resolve the issue, professional servicing is recommended.

Frequently Asked Questions

What is an air source heat pump, and how does it work?

An air source heat pump extracts heat from the outside air, similar to how a fridge extracts heat from its interior. It uses this heat to warm up your home and water. Even when the air outside is cold, the pump can efficiently extract heat, making it a versatile option for the variable Sussex climate.

Are air source heat pumps suitable for homes in Sussex?

Yes, ASHPs are very suitable for Sussex homes. The region’s generally mild climate means the heat pumps can operate extremely efficiently. Plus, in rural Sussex areas not connected to the gas grid, ASHPs offer a particularly effective alternative to oil-fired boilers.

What are the benefits of installing an ASHP in Sussex?

The benefits include lower heating bills, reduced carbon emissions, and potential eligibility for government incentives like the Boiler Upgrade Scheme (BUS). In addition, ASHPs can work in tandem with other renewable technologies such as solar panels, which are also viable in Sussex due to decent levels of sunlight.

How much does it cost to install an ASHP?

The installation cost can vary depending on your home’s specifics, but generally, it ranges from £6000 – £9000 (inclusive of a BUS grant). This upfront cost can be offset by lower running costs and government schemes available to Sussex residents, which help make the transition more affordable.

You can check your eligibility here.

What maintenance does an ASHP require?

ASHPs need relatively little maintenance, but regular checks are recommended to ensure optimal efficiency. This includes professional annual inspections and simple homeowner checks like ensuring the outdoor unit is clear of debris. OHM Energy offers ongoing support and maintenance services, ensuring that any issues are promptly addressed and keeping your system running smoothly year-round.