What happens during a heat pump survey and heat loss check? March 26, 2026 A professional heat pump installation begins with a comprehensive survey to understand your home’s heating needs. This step ensures optimal comfort, efficiency, and system longevity. What a proper heat pump home survey includes A proper survey involves more than a quick inspection—it collects detailed data to accurately calculate heat loss and design an efficient heating system. The installer will usually go room by room, measuring, checking construction details and asking how you use your home. You should expect the survey to take at least 1 to 2 hours for a typical house, and longer for larger or more complex properties. Room-by-room heat loss: measuring each space to calculate how much heat it needs on the coldest days. Insulation and glazing check: walls, loft, floors, windows and doors, plus any draught points. Emitters and pipework: radiators, underfloor heating, pipe sizes and routes. Hot water demand: bathrooms, showers, occupancy and usage patterns. Outdoor and indoor unit locations: siting for the heat pump, cylinder and controls. Room-by-room heat loss and insulation assessment Heat loss calculations are the foundation of good heat pump design. Using your room dimensions, construction type and insulation levels, the installer works out how many watts of heat each room needs at a given outdoor temperature. This is different to gas boiler sizing, which is often done on rough rules of thumb. For heat pumps, accurate figures are essential so the system can run at a lower flow temperature without leaving rooms cold. Radiator, underfloor and pipework checks Once the heat loss is known, the installer looks at your current emitters. Radiators are measured so they can be matched to the room heat loss at lower flow temperatures. In many homes some will be reused, some upsized and a few added where needed. Underfloor heating is assessed for pipe spacing, floor build-up and controls. Pipework is checked to make sure sizes and layouts will let the system circulate enough water efficiently, avoiding noisy pumps and cold spots. Hot water demand and cylinder space A heat pump almost always pairs with a hot water cylinder. During the survey the installer counts bathrooms, showers and large baths, and talks through how and when your household uses hot water. They then identify where a cylinder, buffer or volumiser could be located, how it will be connected, and whether any structural or access issues need planning in advance. Finding the right locations for equipment The outdoor unit needs good airflow, suitable clearances, a solid base and compliance with noise guidance. The installer should check boundaries, windows and neighbour proximity, and discuss options with you. Indoors, they will look at plant room or cupboard options, routes for insulated pipework, and where to position controls so they are accessible and easy to use. From first call to commissioning: a typical timeline A reputable installer will follow a clear process with documented stages. Although every project is unique, most follow a similar journey. Step 1: Initial enquiry and pre-survey discussion This starts with a phone call or online enquiry. The installer should ask about your property type, current heating, any known issues and your goals, such as improving comfort in certain rooms or reducing carbon. They may request photos, floor plans or an EPC before the visit. This helps make the on-site survey more efficient and focused. Step 2: On-site survey and data gathering During the visit, all the measurements and checks we have covered are carried out. They may also take loft photos, note electrical supply details and check drainage routes for condensate. You should have plenty of time to ask questions about how the system will look, sound and operate day to day. Step 3: System design and heat loss report After the survey, the installer completes formal heat loss calculations using specialist software or spreadsheets. They then select a suitable heat pump size, cylinder, emitters and controls based on that data. This is also where flow temperature optimisation is done, aiming for the lowest practical flow temperature that still keeps the house warm. Lower flow temperatures usually mean higher efficiency and lower running costs. Step 4: Detailed quotation and documentation Once the design is ready you should receive a written quote with a clear specification. A quality installer will also provide supporting documents such as: Heat loss summary: at least an overview, with room-by-room detail available on request. System schematic: showing how the main components connect. Product data sheets: for the heat pump, cylinder and key controls. Outline performance expectations: including design flow temperature and seasonal efficiency assumptions. A thorough survey goes beyond a basic check, gathering all the details needed to create an efficient, tailored heating solution. Step 5: Installation planning Once you decide to proceed, dates are agreed and pre-install checks confirmed. This may involve liaising with your electrician, builder or kitchen/bathroom fitter if other work is happening at the same time. The installer should provide a simple outline of what will happen each day, who will be on site, and how disruption will be managed. Step 6: Installation and commissioning During the install, old equipment is removed, pipework modified, the heat pump and cylinder installed, and wiring completed. Good installers protect floors, keep you updated and leave the property tidy at the end of each day. Commissioning follows manufacturer and industry best practice. This includes system flushing where required, correct inhibitor or glycol dosing, pressure checks, setting up controls and recording results on formal commissioning sheets. Step 7: Handover, fine-tuning and support At handover you should be walked through how to use the system and what to expect in different seasons. Controls should be set up simply, with any advanced features explained in clear terms. The installer may schedule a follow-up visit or call after a few weeks to fine-tune flow temperatures and timings once the system has settled in. What can go wrong if installers take shortcuts When heat loss calculations are skipped or rushed, the usual result is either an oversized or undersized system. Oversized units tend to cycle on and off too frequently, reducing efficiency and shortening component life. Undersized systems may struggle in colder weather, leaving some rooms cool or relying too heavily on electric backup heaters. In both cases, energy bills and comfort suffer compared with a properly designed system. Shortcuts with radiator sizing, flow temperature optimisation or commissioning can also lead to noisy pipework, poor hot water performance and confusing controls that are never quite set up correctly. Special considerations for older homes and underfloor heating Older properties with solid walls, original single glazing or limited insulation need extra care at the design stage. The survey should include detailed questions about planned upgrades, and sometimes staged improvements are sensible before or alongside the heat pump install. Listed buildings add another layer of complexity, with restrictions on external appearance and internal alterations. A good installer will work with you and, where needed, your conservation officer to find suitable locations for the outdoor unit and internal pipework. Where space for a cylinder is tight, creative solutions such as slimline cylinders or reworking existing airing cupboards may be explored. The key is to plan these early so there are no surprises once works begin. For underfloor heating projects, more time is spent on floor build-ups, manifold locations and zoning. This can be an excellent match with heat pumps due to the low water temperatures, but it relies on careful design rather than on-site guesswork. Heat pump survey checklist you can copy To help you compare installers, you can copy this simple checklist and tick items off during quotes and visits: Room-by-room heat loss calculations offered and shared on request Clear plan for radiator or underfloor emitter sizing at lower flow temperatures Insulation and air-tightness improvements discussed where relevant Written design summary, system schematic and product data sheets provided Commissioning sheets and follow-up support included as part of the service Next steps for homeowners in Petersfield, Midhurst and the New Forest If you live in or around Petersfield, Midhurst or the New Forest and are considering an air source heat pump, a detailed survey is the best place to start. To book a home survey or discuss your project in more detail, contact Clean Heat Solutions Ltd on 07391473964. We will guide you through each stage from first call to commissioning, with clear explanations and a focus on long-term comfort and efficiency.