Radiator Upgrades for Heat Pump Compatibility

Why Some Radiators Need Upgrading

A gas boiler pushes water around your system at 65–75°C. A heat pump runs most efficiently at 35–45°C. At lower flow temperatures a radiator gives off less heat, so a radiator sized for a boiler may not deliver enough warmth for the same room when the source changes.

This is not a flaw in the technology. It is a design parameter, and it is exactly the kind of detail that separates an installation that works in February from one that generates a one-star review. Undersized emitters force the system to run hotter, which collapses the COP and drives up the bills.

How We Assess Your Radiators

During the heat loss survey, every room's measured heat loss is compared against the output of its existing radiator at heat pump flow temperature. The result is a room-by-room verdict: keep, or upgrade. Nothing is replaced that does not need to be, and nothing that needs replacing is quietly left in.

Larger Radiators & Lower Temperature Operation

Where an upgrade is needed, we specify a radiator whose output at 40°C flow meets the room's heat loss with margin. Modern K2 and K3 panels deliver substantially more output in the same wall space, in most rooms the upgrade is invisible to the eye and transformative to the system's efficiency.

When Radiator Replacement Is Necessary

Typically two to five radiators in a pre-1980s house, most often in the largest rooms and any room with high glazing area. Some houses need none. Your survey report tells you exactly which, and why, with the numbers shown.

Cost & Installation Timeline

Radiator upgrades are itemised inside the same fixed written quote as the heat pump, one document, one price, BUS grant on the face of it. They are installed within the same three-day project by the same directly employed engineers. No second contractor. No coordination overhead. No surprise invoice.

Radiator Upgrades Included in Your Fixed Quote

The price you are given is the price you pay. If the survey specifies four radiator upgrades, they are in the quote before you sign, not discovered on day two and added to the bill.