Stupid questions time! If I have fewer radiators on, does it cost less to heat?

[notwhatineednow]

So, if the boiler is heating water anyway and sending it round the system, does it make a difference if one or more of the radiators is turned off?

Does it take less energy to heat the remaining radiators and therefore is cheaper?

Or is it heating the water and sending it round the system anyway, and would cost the same even if all the radiators were off.

I'm leaning towards the first, but really not sure!

my understanding is less rads on cheaper as it dose not have to fire up one's not on so less firing up

thats my understanding probably wrong

it's like a pen if you have to write 10 words on a line you will use more ink than if you only have to write one word on a line lol

I hope so as we’ve turned loads off.

In my understanding
It reduces in 2 ways

1. Part of the circuit is closed so there is less water circulating so less water needing to be heated

1. Heat is only being lost in the pipes that are heating up so there is less heat being lost - especially as unused rooms tend to be colder to start with.

Counter to this is that some heat will leak from heated areas to unheated areas