Why Notify the DNO for a Heat Pump Installation?

• Grid Safety & Compliance – Ensures the network can handle the additional electrical load.

• Pre-Approval for Larger Systems – If your heat pump exceeds certain thresholds, a DNO application must be submitted before installation.

• Post-Installation Notification for Smaller Systems – If your heat pump falls within standard limits, a simple notification is required after commissioning.

• Avoiding Supply Disruptions – Prevents potential voltage fluctuations or overloading the grid.

• Ensuring a Smooth Installation Process – Avoid delays or unexpected costs due to network constraints.

How It Works

1. Determine Your Application Type

G98 Notification (for heat pumps up to 3.68kW per phase / 11.04kW three-phase)

• Installation can proceed immediately without pre-approval.

• DNO must be notified within 28 days after commissioning.

G99 Application (for heat pumps above 3.68kW per phase / 11.04kW three-phase)

• Requires pre-approval from the DNO before installation.

• Application process typically takes 30-60 days for approval.

2. Submit Your DNO Application or Notification

• If your heat pump qualifies for G98, complete the post-installation notification form.

• If your heat pump requires G99 pre-approval, submit a formal application before installation.

3. DNO Review & Response

For G99 applications, the DNO will assess the impact on the grid and either:

• Approve the connection (with or without conditions).

• Request grid upgrades or modifications.

• Suggest alternative connection options.

4. Installation & Final Notification

• Once approved, the installation can proceed.

• A final commissioning report may be required by the DNO to confirm compliance.

Who Needs to Apply?

Our DNO application and notification service is essential for:

• Renewable Energy Installers – Installing air source and ground source heat pumps.

• Electrical Contractors – Ensuring compliant connections for high-power installations.

• Businesses & Homeowners – Seeking approval for large heat pump installations.

Avoid delays and ensure your heat pump installation meets all regulatory requirements.