What Consumer Unit Do I Need for a Heat Pump?
A heat pump normally needs a dedicated final circuit and protection selected around the exact appliance. The right consumer unit is therefore the one that accommodates the manufacturer's required protective devices, the design current, starting characteristics, supply capacity and any surge or load-management requirements.
Quick answer: Use a consumer unit or dedicated heat-pump board that is compatible with the required MCB/RCBO and RCD type, has adequate current and breaking-capacity ratings, and leaves enough usable ways for the full control and ancillary arrangement.
Do not specify Type A or Type B from the words “heat pump” alone. The manufacturer must state the residual-current characteristics and protective-device requirements for the exact model.
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Does a Heat Pump Need a Dedicated Consumer Unit?
A heat pump will normally have a dedicated circuit, but it does not automatically require a separate consumer unit. An existing board may be suitable if it has verified spare capacity, compatible protective devices and the necessary isolation and circuit arrangement.
A dedicated heat-pump board becomes attractive where the existing consumer unit lacks space or compatibility, where a different RCD type is needed, or where the installation benefits from a clearly separated protection package.
| Existing Board May Suit When | Dedicated Board May Suit When |
|---|---|
| Compatible device range is available | Required RCD type is not available for the existing board |
| Adequate spare ways and thermal capacity | Existing board is full or unsuitable |
| Supply and diversity assessment are satisfactory | Load management or dedicated metering is required |
| Manufacturer requirements can be met | A packaged heat-pump protection arrangement reduces site complexity |
Which RCD Type Does a Heat Pump Need?
Start with the heat-pump manufacturer's instructions. Inverter-driven equipment can produce residual currents that an ordinary Type AC device is not designed to recognise. Type A may be suitable where pulsating DC is expected; Type B or a manufacturer-defined specialist type may be required where smooth DC or other waveforms can occur.
A blanket statement that “every heat pump needs Type B” is wrong. So is assuming that Type A always suffices. See Type A vs Type B RCDs for Heat Pumps.
How Do You Select the Breaker or RCBO?
- Use the design current and maximum protective-device rating declared by the manufacturer.
- Check starting or inrush current before selecting B-curve or C-curve protection.
- Verify cable current-carrying capacity, voltage drop and disconnection requirements.
- Confirm breaking capacity and board compatibility.
- Separate residual-current type from overcurrent curve; they describe different characteristics.
Where an RCBO is used, both the overcurrent and residual-current functions must match the equipment and circuit.
Is a 100A Single-Phase Supply Enough for a Heat Pump?
Often, but the service-fuse label alone cannot answer the question. Assess the whole property load, diversity, existing EV charging, electric cooking, immersion heating, batteries and any other high-demand equipment.
Load curtailment or monitoring may avoid an unnecessary supply upgrade where it is designed and permitted correctly. The Load Balance Monitoring Relay is one option for compatible arrangements.
Does a Heat Pump Need Surge Protection?
Modern heat pumps contain sensitive electronic controls and inverter components, so transient-overvoltage protection should be assessed under the applicable BS 7671 requirements. Coordinate any SPD at the origin with additional protection required near a remote outdoor unit.
Manufacturer first: Record the required RCD type, maximum protective-device rating, isolation method and any neutral-switching or SPD conditions from the exact heat-pump manual before ordering the board.
Heat Pump Consumer Unit Checklist
- Single-phase or three-phase supply
- Design current and manufacturer maximum OCPD
- MCB/RCBO curve and breaking capacity
- Required RCD type and residual-current rating
- Number of usable ways, including controls and backup heater
- SPD requirement and coordination
- Local isolation and enclosure location
- Whole-property maximum demand and load management
A packaged option is the 8 Way Heat Pump Consumer Unit with Type B HP RCD.
Heat Pump Consumer Unit FAQs
Does a heat pump need its own circuit?
Normally yes, subject to the manufacturer's instructions and the installation design.
Does every heat pump need a Type B RCD?
No. Select the RCD type from the manufacturer data and expected residual-current waveform.
Can a heat pump share an existing consumer unit?
It can where the board has suitable capacity, compatible devices and a compliant circuit arrangement.
Should I fit a C-curve breaker?
Only where the starting characteristics justify it and the circuit still meets the required disconnection conditions.
Final Word
There is no universal “heat pump consumer unit”. Match the board and protective devices to the exact appliance, then check space, supply capacity, surge protection and the rest of the property's electrical demand.
Specifying the board? Compare heat-pump consumer units and accessories.
For the wider installation, browse consumer units and RCDs.