Choose on design method, not on price. Insist on a room-by-room heat loss calculation to EN 12831-1, a stated design flow temperature of 45 °C or lower where the building allows, a named radiator schedule and a commissioning record. In the UK, MCS certification is the sole route to the £7,500 Boiler Upgrade Scheme grant.
What separates a good heat pump installer from a cheap one?
One thing above all: whether they design the system or simply size the box. A good installer arrives with a measuring tape and leaves with a room-by-room heat loss figure. A poor one asks the size of your old boiler and quotes a heat pump of the same output — which is how oversized, short-cycling, 55 °C systems get built.
The four deliverables that identify a competent installer before any work starts:
- A room-by-room heat loss calculation to BS EN 12831-1:2017, not a floor-area rule of thumb.
- A stated design flow temperature, with the radiator schedule that achieves it.
- A cylinder specification including indirect coil surface area in m², not just litres.
- A commissioning plan: measured flow rates, weather compensation curve, and a handover record.
Which certification does the installer actually need?
| Market | Required installer status | Why it matters |
|---|---|---|
| United Kingdom | MCS certified | The sole certification route for the Boiler Upgrade Scheme in 2026 |
| France | RGE, QualiPAC for heat pumps | Mandatory for MaPrimeRénov', CEE and the éco-PTZ |
| Germany | Specialist firm or energy-efficiency expert confirmation (BzA) | Required for the KfW 458 application, which must be filed before work starts |
| Ireland | SEAI-registered installer plus technical assessment | Condition of the SEAI heat pump grant |
| Italy | Qualified installer, GSE application after works | Condition of Conto Termico 3.0 |
| EU-wide | F-gas certification under Regulation 2024/573 | Required for refrigerant handling; updated training covering natural refrigerants such as R290 was due from 12 March 2026, with national certification programmes to be adapted by March 2027 |
Certification is a floor, not a ceiling. It proves the paperwork will be valid; it does not prove the design will be good.
What ten questions should you ask before signing?
- What is my calculated heat loss in kW, room by room, and at what outdoor design temperature?
- What design flow temperature is the system built around?
- Which radiators are you replacing, and to what output at that temperature?
- What is the cylinder's indirect coil surface area in m²?
- Am I getting a buffer tank, and why or why not?
- What SCOP do you expect at my design flow temperature, and from which test data?
- Where exactly will the unit sit, and what is the predicted sound pressure at my neighbour's boundary?
- Which electrical works are included, and have you checked the supply capacity?
- Who submits the grant application and when do I pay?
- What is covered by your workmanship warranty, and is it insurance-backed?
An installer who answers all ten without hesitation is worth paying more.
What are the red flags?
- A quote produced without a site visit, or sized from the old boiler's output.
- No heat loss document, or a single whole-house number with no room breakdown.
- "Your existing radiators will be fine" said before any radiator was measured.
- The cylinder described only in litres.
- A design flow temperature of 55 °C offered as the default rather than as a considered compromise.
- Pressure to sign an unconditional contract before the grant application is lodged — in Germany any contract signed before the KfW application must contain a suspensive or resolutory condition, or the grant is lost.
- A price far below the market range in what does a heat pump cost to install?. Cheap quotes usually omit emitters and the cylinder.
Who signs off the work?
The installer commissions, but you should receive the evidence: measured primary flow rate, the weather compensation curve as set, the anti-legionella schedule, and the manufacturer registration that activates the parts warranty. Keep the heat loss calculation with the deeds — it is the document a future buyer, a service engineer and any warranty claim will all want.
Solimpeks works with dealer and installer partners across the 96+ countries it serves for exactly this reason: a well-made heat pump or collector installed on an undersized emitter circuit performs like a badly made one. The design is the product.
Frequently asked questions
How many quotes should I get for a heat pump?
Three is the practical number, and all three should be given the same heat loss calculation to price against. If each installer produces a different heat load, you are comparing three different houses rather than three offers.
Does the installer have to be certified to get a grant?
Yes in every major European scheme. MCS in the UK, RGE in France, SEAI-registered in Ireland, a specialist firm or energy-efficiency expert confirming the application in Germany. Using an uncertified installer forfeits the grant entirely, which almost always costs more than it saves.
Should I choose an installer tied to one manufacturer?
Single-brand installers often know their hydraulics and controls deeply, which is worth a great deal. The risk is that every house gets the same answer. Judge them on the heat loss survey and the flow temperature they propose.
What if my installer goes out of business?
Manufacturer warranties on the equipment survive, but workmanship cover does not. Ask whether the workmanship guarantee is insurance-backed and check whether your national scheme offers a consumer code with a dispute route.