[pretendgeneer]

That's not true. Heat pumps are cheaper to run than gas heating, I removed my old single room gas heater for a ducted split system total cost reduction was 30% even before Russian invasion caused gas prices to spike. And house is much warmer.

Gas boilers generally produce much hotter water, so the radiators they use tend to be small.

Heat pumps gain more efficiency if you can reduce the output temperature. So running a heat pump at max efficiency through radiators designed for a gas system, won't put out as much heat into the room.

So you have two options, increase the size of the radiators or increase the insulation. It's better to increase the insulation as you gain the benefit of both warmer room and less energy required to heat a room.

[jibbit]

I can assure you it is true, but for transparency’s sake I will say that I have no idea what a single room gas heater is.. I’m pretty sure it isn’t what we are talking about here. Neither do I no what a ducted split system is.