The short version
- Not every radiator needs replacing — usually a handful do
- Double-panel, double-convector radiators do most of the work
- Pipework diameter can limit flow to certain rooms
- Underfloor heating is the ideal emitter, but not a requirement
How we decide which radiators change
Room by room, we compare required heat output at the design flow temperature against what the existing radiator can deliver.
- Measure each radiator's dimensions and panel type
- Calculate the room's heat loss
- Compare output at low flow temperature, not at boiler temperature
- Flag rooms where pipework diameter restricts flow
- Prioritise the rooms that already feel cold on gas heating
What low-temperature heating feels like
Radiators feel warm rather than hot, and the system runs for longer periods rather than blasting and stopping. Homes stay at a steadier temperature. People who set a heat pump up like a gas boiler — big setbacks, short bursts — are the ones who end up disappointed.
Doing it in stages
Some households upgrade key radiators while still on gas, then move to a heat pump later. That spreads the cost and improves comfort in the meantime, provided the emitters chosen are sized for the future flow temperature.
Common questions
Do I need to replace every radiator?+
Rarely. Most homes need a few specific rooms uprated.
Is underfloor heating required?+
No. Correctly sized radiators work well at heat pump flow temperatures.
Will bigger radiators look intrusive?+
Depth increases more than width in most cases; we plan positions with you.
Can I upgrade radiators before deciding on a heat pump?+
Yes, and it's a sensible staged approach if sizing is done for the future system.
Thinking about a heat pump?
We'll tell you exactly which radiators would need to change.