Heat Pumps FAQ’s

Yes, heat pumps have been designed with heating in mind and the UK government are actively encouraging households to replace their traditional gas boilers for these greener alternatives with the Boiler Upgrade Scheme (link to our page on incentives). Specifically, a heat pump (ground source, air source or water source) uses the constant ambient temperature/ energy in either the ground, air or water to evaporate a refrigerant gas in the heat pump which then is compressed which super heat the gas which is then transferred to the house heating and hot water circuits via under floor heating, radiators and/ or to heat a hot water cylinder. Typically a modern heat pump can get the heating water up to 65 degrees.

There are a few factors to take into account here such as the size of the house, the current or expected heat loss which will be calculated using the properties u-values and insulation thicknesses, for a average house of approximately 4 bedrooms and a heated floor are of around 200m2 with average insulation levels, a 12kW unit would be sufficient.

There are two main types of Ground Source Heat Pump; a vertical/borehole system; or a horizontal/slinky system. Both have their benefits, for example a borehole will use less space and can go as deep as 200m, typically spaced between 5 and 10m apart however will require access for a borehole rig whereas a horizontal system is considerably cheaper but you will need around 10m of trenching per kW of heatpump and a minimum of 5m between trenches is recommended. 

An ASHP can be installed almost anywhere around your property however the further you put the unit from the house, the more heat will be lost in the insulated flow and return pipework that runs back to the property. We use the highest quality pre insulated pipe possible however we always recommend tucking it away as close to the property as possible. That being said we have installed heat pumps at the bottom of gardens however this increases the overall cost due to the additional pipework and time to install.

A ground source need far more space than air source for the heat collector. Typically the collector Weill be installed in a paddock (if horizontal) or a garden (if a borehole). The low grade heat gained from the ground then runs back to the property gaining low grade heat on the way where the internal heat pump unit is located. The internal ground source unit can be installed in either a garage or utility room cupboard. Typically you need a minimum of 1.5m x 1m cupboard space for the internal ground source unit.

Depending on whether you are considering a Borehole or horizontal system will change this answer, we typically see Horizontal Ground Source Heat Pumps starting at around £25k+ for a small system however a borehole system is typically around 25% more expensive than horizontal due to the specialist equipment needed however with a borehole you can go up to 200m deep, potentially reducing the number of boreholes compared with horizontal trenches thus saving considerable external space.

The simple answer is no, or no accurate ones anyway and there is a simple reason for this, it’s simply too detailed and bespoke to try and make a standardised calculator as every property is so different with size of property, heat loss of property, garden size and space, access etc. As an example, when we do our initial desktop assessment we tend to look at the entire property, including insulation levels and u-values which will then give us an estimated Heat Loss Value in kW, we then have to size the Heat Pump from that we work out how many ground loops are required to satisfy the load of the property/properties and assess the available space externally. 

Essentially, a Ground or Water Source Heat Pump works like a ‘reverse refrigerator’, taking low grade heat from either the ground or body of water, and turning into usable heat within the home. via the refrigeration process and a compressor within the heat pump. (Basically pumping heat from one place to another).

There are two main types of ground source, horizontal systems and vertical borehole systems, and the concept of both is the same. Using the year-round solar gain of the sun within the ground which acts like a solar heat battery, with an average temperature of around 12C. A closed pipe system laid within the subsoil by Baystar known as collectors, capture the ambient heat in a transfer fluid, a heat exchanger within the heat pump then uses this liquid to evaporate a refrigerant liquid, similar to the one used in domestic and commercial fridges. The evaporated refrigerant is compressed inside the Heat Pump, raising its temperature much higher. A heat exchanger then ‘robs’ this higher heat, transferring it into your building’s internal heating network, powering radiators and underfloor heating systems, and delivering piping hot running water. Whether you have a horizontal or vertical ground source system put in place will depend on the space available around your property, but both are very similar in performance. 

This is something we would strongly advise against due to the complexity of these systems, we would always recommend using an MCS accredited professional like Baystar with years of experience to install your renewable systems. What you can do is preparatory work prior to the install to reduce overall costs such as digging trenches for a horizontal system or removing the previous heating system. if you’d like to discuss ways to effectively reduce costs you can always reach out to an MCS installer like Baystar. We have over 12 years experience in installing ground source heat pumps and can help with every element of an install.

Your heat pumps filters or strainers are likely located in the pipework near the main unit, if you are looking to clean the filter, make sure you turn off the power to the heat pump or any secondary pumps. You will be able to get full instructions on the whereabouts and how to replace the filter in the handover document supplied by your installer, this will include the owner’s manual from the manufacturer of the unit. Feel free to give Baystar a call if you would like to service the unit for you to give you complete piece of mind.

The compressor is the core component of a heat pump and can be found inside the heat pump unit, consult your owners manual for parts and information. Alternatively feel free to give Baystar a call if you would like us to service your system. We have competitive service packages available.

This refers to the buried collector coils for a ground source system and will typically be found in a localised field or garden close to the property. A geothermal heat pump is the same as a ground source heat pump where the energy is coming from the solar energy stored in the ground. It is a misconception that it is geothermal energy coming from the earths core, other than some exceptional cases. Usually any usable heat from the earths core is miles under the ground, we install collector up to 200m down, therefore any energy from the earth core will be negligible and it is the suns stored geothermal energy that we are tapping into.

Refrigerant will pass between the main components of the compressor, condenser, expansion device and the evaporator to transfer heat from the ambient air to your indoor heating emiters. So refrigerant is only in the internal components of the heat pump only. There are some rare cases where refrigerant has been used in the collector pipes, however this is not the way of a conventional heat pump.

There could be many reason why the unit is not providing heat depending on if it is an air source or ground source heat pump. Common reasons that a heat pump system may not be heating as intended may be the external air source unit is blocked by leaves or debris preventing it from pulling in air and needs cleaning or replacing – this is important as it can block airflow to the compressor which is a part of the unit that heats; refrigerant levels are low – this could be due to a leak – and needs to be topped up. Or it could be an issue on the house heating side such as not enough pressure in the system, a circulation pump not working or may even be air in the radiator or underfloor circuits. 

These are just common things to check before calling an engineer however there are a myriad of reasons that your unit may not be working. Usually, an error code will be displayed that has a corresponding reason for it’s fault. Feel free to call us to discuss the error code as there may be support we can give over the phone to get the unit working again. Alternatively, we can arrange a site visit by a qualified engineer to investigate and rectify the fault.  

A frozen heat pump occurs when the air outside has a high moisture content which then gets trapped between the evaporator blades and freezes which will cause the unit to go into defrost mode, most units are adjusted to cope with different climates however if they haven’t been adjusted for UK climate this will likely cause disruption to the heating cycle. It is very important to select a quality heat pump unit and make sure to check reviews and online forums on the heat pump you intend to install. We have years of experience with heat pumps and can offer help when selecting a unit and can advise on units to steer clear of as you can have the best installer in the world but if the actual unit itself is poor then ultimately you will have problems.

Microbore pipework is particularly popular in properties built I the 80s and 90s. Traditionally a heat pump needs larger pipes as the flow temperature is lower. To avoid a heat pump from overworking and reducing it’s lifespan it is recommended you replace the heat emitters and up size the piping, however it is worth getting the installation engineer to inspect your current system as they may be able to advise you on your system. Feel free to give us a call for a system inspection.

Technically, yes it will run however the refrigerant is the key part of the heat pump that transfers the heat from ambient temperature outside to the heat exchangers within the system and to your homes heating system so without it you won’t have heat in your home so has no benefit to run it without refrigerant 

This is a voluntary best practice scheme,of which the standards define a high level of design, installation quality and maintenance to protect the environment and maintain the reputation of the industry. They are designed to help contractors and sub-contractors employing specialist companies to install ground source systems that comply with these Standards. Baystar hold this accreditation and are experts in heat pump technology with decades of experience.

Ground Source Heat Pumps are considered to be low carbon or greener and therefore better for the environment as they use less energy than a conventional gas or LPG system however as they still require electricity to run they can only be counted as renewable if that electricity is generated through a renewable source such as solar, wind turbine or similar. Baystar often install heat pumps alongside solar to allow the system to be considered as fully renewable.

Yes, however it is always worth remembering the output of your solar system needs to meet the demands of the heat pump which will de different depending on the make and model. Call Baystar for further guidance on this and we can advise on what is best for you.

A heat pump cannot create electricity, it simply moves energy from one place to another and therefore requires an input of energy to allow that transfer to take place. If you pair your GSHP with a solar array you can essentially run it for free (not including the installation and maintenance cost) 

A GSHP can be used anywhere that has a demand for heat that has the appropriate land available for the collector loops either in a horizontal or borehole form. The actual heat pump is usually stored in a plant room in the property or an outbuilding. Heat pumps can also be used to generate simultaneous heating and cooling as the by product of either process is either heating or cooling. So in heating mode you can essentially get free cooling and visce versa.

In the UK the most commonly installed heat pump is an Air Source Heat Pump. In 2019 there was a reported 238,823 heat pumps only 36,877 were Ground or Water Source Heat Pumps, the remaining 201,946 are Air Source Heat Pumps – 55,000 heat pumps were sold in the UK in 2022. This is considerable less than our European counterparts (the UK has 412 per 100,000 people compared to the European average of 3068 per 100,000 people) as an example in the same year France recorder over 620,000 heat pump sales in the same year, however the UK government has made a pledge to roll out 600,000 heat pumps by 2028. 

source: Heatpumps.london blog and statista

This is mainly down to the cost as air source is considerable cheaper, however there can be far greater efficiencies in ground or water source heat pumps.

A GSHP will always have a better efficiency in a colder climate as the ground will always maintain a fairly steady temperature whereas an ASHP may suffer in temperatures lower than 3 degrees, again depending on make, model and climate.  

  • MCS = Microgeneration Certification Scheme is a standard that allows for the certification of products, installers, and the installations themselves of low carbon products/installations. This is a UKAS accreditation to ISO 17065. This is a requirement to benefit from any government scheme 
  • CHAS = Contractors Health & Safety Assessment Scheme, this is an industry safety standard accreditation
  • Construction Line = is a register for pre-qualified contractors in the construction industry.
  • Gas Safe = the official gas registration body for the UK, by law all business that operate with gas must be on this register. Baystar on occasion will remove outdated gas systems and as such we must be Gas Safe Registered.
  • F-Gas Certification = This is a certification to work with refrigerant gasses and the systems that require refrigerant gasses such as all heat pumps 
  • NICEIC Approved Electrical Contractor and Domestic Installer = This is an Electrical accreditation that means we are government approved electrical installer for both commercial and domestic dwellings and allows us to certify our work in accordance with 2391 test and inspect regulations
  • NAPIT = This is another government approved accreditation for Microgeneration Technologies meaning the homeowner can benefit from government incentives such as BUS or SEG, this is also linked to our Workmanship Warranties.
  • BESA (formerly HVAC Association and later B&ES) = This is a trade association for companies that design, install, commission, and maintain heating, ventilation, air con, refrigeration, and related engineering services. 
  • REFCOM Certification = voluntary best practice company registration scheme focusing on F-Gas systems.
  • CQMS Safety-Scheme = is a UKAS-accredited Type C Inspection Body under ISO 17020:2012 for the provision of health and safety assessment services’
  • HETAS = Heating Equipment Testing and Approval Scheme is a competent person scheme for installers of biomass and solid fuel heating, registration for retailers and chimney sweeps and approval of appliances and fuels.
  • GSHP Association = this is another voluntary best practice scheme, standards define a high level of design, installation quality and maintenance to protect the environment and maintain the reputation of the industry. They are designed to help contractors and sub-contractors employing specialist companies to install ground source systems that comply with these Standards.
  • Renewable Energy Consumer Code (RECC) = high consumer protection standards for businesses who are selling or leasing renewable energy generation systems to domestic consumers. RECC is approved by Chartered Trading Standards Institute as part of the Consumer Codes Approval Scheme and is also a TrustMark Scheme Operator
  • CIOB = Chartered Institute of Building is a UK-based international professional association which exists to promote and advance for the public benefit the science and practice of building and construction. Jonny holds this membership directly.

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