Heat pump paperwork: The records and sign-offs homeowners must keep

Installing an air source or ground source heat pump is one of the most substantial mechanical upgrades a property can undergo. Unlike replacing a conventional gas boiler like-for-like, a heat pump installation touches multiple regulatory frameworks, electrical grid requirements, and bespoke design calculations. Without the correct paperwork in place, servicing the equipment or demonstrating compliance when you come to sell can become unnecessarily complicated.

Whether you are planning an installation or have recently had works completed, understanding which documents to request from your installer and store permanently will protect your investment.

1. MCS certificate and Building Regulations compliance

In the UK, most domestic heat pump installations are carried out under the Microgeneration Certification Scheme (MCS). An MCS certificate confirms that the system has been designed, installed, and commissioned to recognised industry standards. It is also an essential requirement if you applied for government funding such as the Boiler Upgrade Scheme.

Heat pump installations must also comply with Building Regulations, covering electrical safety, energy efficiency, and sound levels. When using an installer registered with a relevant Competent Person Scheme, they can self-certify the installation and notify your local authority. You should receive a formal Building Regulations Compliance Certificate directly in the post or digitally shortly after completion.

• MCS Certificate: Confirms product and installer compliance, detailing model numbers and generation capacity.
• Building Regulations Compliance Certificate: Proof of local authority notification via a Competent Person Scheme.
• Noise Assessment Calculation (MCS 020): Evidence that external unit sound levels meet Permitted Development criteria under planning rules.

2. DNO application or notification letter

Heat pumps draw a significant electrical load when operating, which means the local electricity network must be informed. Your installer is legally required to notify your Distribution Network Operator (DNO) — the company responsible for the power lines and infrastructure in your area, which is distinct from your energy supplier.

Depending on the capacity of the heat pump and the existing electrical supply to your property, the installer will either follow the 'Connect and Notify' process (often standard for smaller, standard-fit units under Engineering Recommendation G98) or apply for prior approval before installation (under G99). You must keep a copy of the DNO confirmation letter or email acknowledging the connection.

3. Design calculations and commissioning documentation

Unlike a traditional boiler that can simply be turned up to compensate for poor efficiency, a heat pump relies on precise sizing based on the thermal characteristics of your home. A competent installer will have conducted a room-by-room heat loss survey before specifying the heat pump, pipework diameters, and radiator or underfloor heating capacities.

• Room-by-room heat loss calculations: Details the exact heat requirement for each space at low external temperatures.
• Commissioning checklist / Benchmark log: Records system flow temperatures, pressure tests, glycol concentrations, and controller settings.
• Electrical Installation Certificate (EIC) or Minor Works Certificate: Verifies the safety of the dedicated electrical supply and consumer unit connections.

These technical calculations are vital if a future heating engineer needs to troubleshoot performance issues, balance radiators, or adjust the weather compensation curve. Having the original design data eliminates guesswork.

4. Warranties and ongoing service history

Manufacturer warranties on heat pumps typically range from 5 to 10 years, but they are almost always conditional on two factors: registration within a specific timeframe following installation, and an annual service carried out by a qualified technician. Retaining your warranty registration confirmation alongside records of each annual service ensures your cover remains valid.

Because heat pump documentation spans electrical, heating, and structural records, storing physical paper copies alongside an independent digital record, such as Project Passport, keeps the entire system history organized in one location. This makes it straightforward to hand over servicing logs to tradespeople or supply verified documentation to buyers in the future.