Frequently Asked Questions
The following are the most common questions that people ask about heat pumps. If you have any other queries, please don’t hesitate to contact us.
How does a heat pump work?
The simple answer is that it’s like a fridge in reverse. The heat pump takes energy from the ground or air around you and, using a system of heat exchangers and compressors with a refrigerant, multiplies this up to heat which is enough to provide hot water for your heating system and also all of the hot water for your taps.
See our products pages for more details.
Will the heat pump keep me warm enough all year round?
Yes! We will ensure that the system that we design for you is sized to meet the entire heat loss of your house and to deliver all the heating and hot water that you require. The heat pump itself will work perfectly well, even in the middle of winter when it’s well below freezing outside. Our ground source systems are designed and made by Lämpöässä in Finland, where the outside temperature in winter can drop to -45°C, so they take the UK winter in their stride. Our Dimplex air source units are made in the UK and are specifically designed for the UK climate.
How can I work out how big a system I need?
We will undertake a free survey of your home that will allow us to give you an estimate of the heat pump you need and how much it is likely to cost.
If you want to get a quick idea now, however, you could try this rough guide. Look at the number of litres of oil you have used on average over the past couple of years. Multiply this number by 10, then divide by 2,400 to give a rough idea of the heat pump size in kW that you might need. So, if you used 3,000 litres of oil, that would be 12.5 – i.e. you might need a 12.5kW heat pump. The heat pump size may well be less if you have an old boiler, as this is likely to be less efficient.
How much will a heat pump cost?
This depends on how much heat you use. Using the same four bedroom house example mentioned above, it might cost £9,000 for an air source or £17,000 for a ground source. This might sound like a significant investment, but remember the combination of your heating savings and the RHI will usually allow you to get your money back in five years or less. That represents a 20% return on investment.
How long will a heat pump last?
You should expect a good quality air source system should last 15-20 years. A ground source system should last in excess of 30 years. This compares to a modern condensing boiler which is only likely to last between seven and 10 years.
How much maintenance does a heat pump need?
Very little, because the system doesn’t involve combustion. We do however recommend that your system is checked by us each year to make sure that it’s still running as efficiently as it should.
How much will I receive from the RHI?
This depends on how much heat your home needs, which in turn will depend on how big your home is and how much insulation you have.
Use our handy RHI calculator to see how much you could receive in just a few clicks.
As an example, a typical 180m2, four bedroom house previously using 2,880 litres of oil per year, might receive £3,495 per year if they had a ground source heat pump or £1,358 per year if they had an air source. That’s £24,465 over seven years for ground source or £9,506 for air source. The RHI is also tax free and index linked – so the amount you get paid will increase each year with inflation.
Can I receive the RHI and FiTs?
We’re often asked by customers whether they will be eligible for both RHI and Feed in Tariffs (FiTs) if they install a heat pump alongside solar PV. The simple answer is yes – the RHI is payable on renewable heating systems such as ground source, and FiT payments are available for the electricity your installation has generated and exported each time you submit a meter reading to your FIT licensee.
Will the system work with my existing radiators or underfloor heating system?
As the flow temperature from a heat pump is a bit lower than a conventional boiler, it is possible that some of your radiators may need to be slightly increased in size. We will tell you if this is the case when we provide you with a quotation for your system. If you have underfloor heating it should be fine as this is typically designed for a flow temperature which is lower than radiators. Even if you do need a few new radiators, they are not very expensive so you should still get all of your money back well within the RHI period. Even when the RHI payments have stopped, you will still benefit from a big reduction in your heating bills.
Why should I use Finn Geotherm for my system?
Established in 2006, we are one of the longest established heat pump companies in the UK. We pride ourselves on being the renewable heating experts – our only business is, and has only ever been, heat pumps so we’re good at what we do! We only use equipment that we know is reliable and efficient. We also have experience in a huge range of properties of all shapes, sizes and ages for both domestic and commercial use, and have won awards for our installations.
Take a look at our case studies for more details of our past projects.