Heat Pump Electrical Considerations — London 2026
Air-source heat pumps (ASHP) are now mainstream in London thanks to the £7,500 Boiler Upgrade Scheme grant. But before you sign with an MCS installer, the electrical side needs sorting. Here’s what NICEIC electricians want you to know.
Electrical load of a typical 5-8kW ASHP
Most home ASHPs draw 6-12A at full pull (1.4-2.8kW electrical input for 5-8kW heat output). That’s about the same as a kettle continuously. Your existing supply almost always handles it.
What gets fitted electrically
- Dedicated 16A or 20A radial circuit from consumer unit
- RCBO protection
- Outdoor weatherproof isolator near the unit (IP65)
- Bonding to the heat pump body
- Cabling underground or through cavity
Cost (electrical side only)
£450-750 typical for a London install — IF your consumer unit has a spare way. If full, add £450-650 for a board upgrade.
Pre-survey questions to ask
Where will the outdoor unit sit? How far from your fuse board? Single-phase or 3-phase supply? Is your earthing adequate (TN-C-S vs TT)?
Call 07407 627542 for the electrical side of your heat pump install.
