Cold underfloor zones, fixed — and a straight answer on the rest.

Zoning — separate circuits, actuators and zone valves, each opening and closing to control a room or a floor — comes from gas and oil boilers. They needed to hold a high flow temperature and shut circuits off to manage it. A heat pump is the opposite: it’s at its most efficient running low and steady across the whole system.

So wherever we can, we design an open loop — the least zoning, actuators and valves we can get away with. That’s not how most plumbers and heating engineers set a system up, and it’s one of the bigger differences between a heat pump system that runs well and one that doesn’t.

On a system that’s already in, though, it’s a judgement call rather than a recommendation. Undoing zoning that’s already been installed can run to several hundred pounds, sometimes close to a thousand. A zoned system still works and still gives you heat — it just isn’t running as efficiently as it could. So you’ll get a straight opinion on the spot about what we’d change and what that would cost to do. Putting a figure on what you’d save is a different job — that needs a room-by-room heat loss survey, and that’s chargeable. And if you just want the actuator replaced, we’ll supply one and fit it.

On a new installation it’s simpler still. Designing open loop from the start takes cost out of the job — no zone valves, no actuators, no wiring centre, no extra pumps, and none of the labour to fit them.