Installation process

Installing a heat pump is more complex than a standard boiler swap. It involves a “whole house” design approach to ensure the system provides comfort and efficiency.

1. Professional site survey

A qualified MCS-certified installer will visit your home. Unlike a boiler survey, this includes:

  • Heat loss calculation: A room-by-room assessment of your walls, windows, and insulation.
  • Radiator audit: Checking if your current radiators are large enough to work at lower temperatures.
  • Space planning: Identifying the best location for the outdoor unit (away from bedrooms and boundaries) and the indoor cylinder.

2. System design and quote

Based on the survey, the installer will specify the heat pump size (e.g., 5kW, 7kW, or 12kW). They will also apply for your Boiler Upgrade Scheme grant at this stage.

3. Preparation works

Before the heat pump arrives, some “pre-plumbing” may be required:

  • Radiator upgrades: Replacing any undersized radiators with larger ones or adding fans (SMART radiators).
  • Cylinder installation: Most heat pumps require a dedicated “heat pump ready” hot water cylinder with a larger internal coil.
  • Electrical upgrades: Ensuring your consumer unit (fuse box) can handle the load and potentially upgrading your main fuse with the DNO (Distribution Network Operator).

4. Main installation (2-5 days)

The installation team will:

  • Outdoor unit: Mount the heat pump on a solid base or brackets.
  • Pipework: Run insulated pipes between the outdoor unit and your heating system.
  • Controls: Install the sensors, thermostats, and the heat pump controller.

5. Commissioning and handover

Once installed, the system is tested and balanced. The installer must:

  • Set the weather compensation: Ensuring the heat pump adjusts its flow temperature based on the outside weather.
  • Handover pack: Provide you with the MCS certificate, building regulations compliance, and warranty documents.
  • Training: Show you how to use the controls. Note: Heat pumps work best when left on a steady temperature, rather than “timed” like a gas boiler.

Timeframe: A typical air source heat pump installation takes 3 to 5 days. Ground source systems can take several weeks due to the excavation work required.