EVi has teamed with the best manufactures in air source heat pumps.

Air source heat pumps (ASHPs) absorb heat from the outside air to heat your home and hot water. They can still extract heat when air temperatures are as low as -25°C. ASHPs need electricity to run, but because they extract renewable heat from the environment, the heat output is greater than the electricity input. This makes them an energy-efficient method of heating your home. Lower your fuel bills and carbon emissions and generate an income through the Renewable Heat Incentive.

How do air source heat pumps work?

With minimal electricity, air source heat pumps transfer energy from the air into heat to provide all your central heating and hot water needs.

Three main components make up this technology. The evaporator (the first heat exchanger), compressor and condenser (the second heat exchanger) work together using the outside air to create heating and hot water.

The air source heat pump absorbs air through fins at the back of the unit. There is energy in the air that an air source heat pump can use at temperatures as low as -25°C.

Lastly, the colder water from the central heating passes through the heat exchanger and withdraws this heat for use in radiators or underfloor heating and hot water.

Why it’s worth it

They are extremely efficient
Electricity can be sourced renewably
Qualifies you for the government’s Renewable Heat Incentive (RHI)
Constant heating reducing issues with damp
Long lifespan
Easily maintained

0% interest-free loans through EST available—Get in touch to find out more!

Our free survey will help us specify which air source heat pump is best for you.

We will carry out a detailed air source heat pump survey and heat loss report of your property. This will consider the following:

Size of your property
Age of your property
The average low mean temperature in your area
External wall / windows / floor / roof
Insulation levels (u-values)
Maximum expected occupancy
Electricity supply
Available space
Potential planning restrictions

All of these details will be measured and recorded by our trained engineers on a site visit. Alternatively, we can work directly from architect drawings to provide a full specification and estimate.

The Older Building
Some properties are stone or granite built with no cavity wall insulation and, as a result, have thermal bridging, all details we pick up at our initial survey. The more information we have before we start working on the heat loss report, we can provide you with the most accurate specification and make sure it comfortably covers your home heating demands.

The Available Space
Heat pumps are best sited in the open air away from enclosed spaces. When the heat pump expels cold air, the last thing you want is the retaining wall restricting circulation.

The air source unit sits outside your property, so it’s just the hot water tank that needs to be housed inside. If there is limited space in the house, the garage or a small, insulated shed is equally good. We work with a wide range of heat pump ready cylinders and often fit hot water tanks in confined spaces. We will work with you from the survey stage to find the most suitable solution.

The Existing Hot Water Cylinder

At EVi, we ensure you have a heat pump and cylinder in line with government standards. You will most likely find the cylinder you have currently is not heat pump ready. We will advise accordingly during the site visit.

If you are looking to reduce your energy bills, fitting a heat pump is the perfect solution.

A heat pump is a great choice if you look to cut fuel costs or make your project as eco and efficient as possible.

Due to their high efficiency, heat pumps have extremely low running costs. In comparison to oil/electric or LPG boiler, air source heat pump paybacks are unrivalled.

An air-source heat pump is a sure-fire way to reducing your reliance on fossil fuels. Although you will still rely on electricity supply, this can be responsibly sourced from various renewable energy providers.

And whilst the government’s Renewable Heat Incentive (RHI) is available, why not take advantage and have your heat source heavily subsidised?

RHI (Renewable Heat Incentive)

The Renewable Heat Incentive is the amount paid to you, from the government, for having a renewable heat source installed instead of using fossil fuels.

Our initial survey will provide you with an estimate of the expected RHI return. In air source heat pump paybacks, you can receive up to £10,450 over a seven-year period. The amount you will be entitled to will be determined by your property’s Energy Performance Certificate (EPC). To apply for the RHI, you must have a valid EPC dated within the last two years and only then will we be able to confirm the amount of RHI return. EVi can supply this EPC for you.

Maintenance and air source heat pump servicing should be carried out by an accredited and qualified installer.

Each manufacturer stipulates its own air source heat pump servicing criteria, which must be met to carry out the service correctly. In many cases, a yearly service is necessary to keep the warranty valid.

If your service is due, please get in touch with us, and we will arrange a visit.

Servicing checklist:

Glycol check is carried out with a refractometer and gives a reading of the percentage of antifreeze in the system.

Field settings – run through field settings to check they are all as per the manufacturer’s instructions.

Strainer cleaning – we install micro-strainers with our heat pumps to prevent dirt from entering the machine. This dirt collects in a strainer and can affect the flow rates of the heat pump. It is a good idea to clean this out once or twice a year.

Coil cleaning

Safety checks on an unvented cylinder

Immersion – check current and if it is still performing the legionella cycle.


Get in touch with us today to find out how EVi can help you. Call us on 01383 665071 or email us at


  • The heat pump harnesses naturally renewable energy from the air, which means it can save money on your fuel bills and reduce your carbon footprint.
  • Homeowners can benefit from a range of warranties of up to 7 years of parts and labour when installed by a renewable partner.
  • Hybrid heating solutions are available to combine air to the water heat pump with a traditional boiler
  • Very quiet operations are a great first step into a renewable and sustainable heating system for your home.


Get in touch with us today to find out how EVi can help you. Call us on 01383 665071 or email us at

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