Heating

[chefalo]

How can I work out how much it will cost to put radiators on for an hour.

[Atheist]

I don't think you can, there are too many variables. How big is the house? How many and what size radiators? Ouside temperature? Inside temperature? Type of fuel? Price of fuel? And so on.....
Sorry.
Can't you get an idea from examining your recent bills?

[Ken4155]

Surely the first hour will cost more than subsequent hours as it must use more energy to get the heating up to the required temperature than to maintain that temperature?

[gingejbee]

Without a smart meter, and assuming you're using gas as the fuel...I think the best you can do is to take an accurate gas meter reading, run the system for a period of time, take another reading, see how much you've used. Then use your tariff (cost per unit) to calculate the hourly cost (assuming you haven't used gas for anything else!).

[barry1010]

The gas meter is not as simple as the electric meter and you have to a calculation to change the number of units used to the amount of gas. https://www.gov.uk/guidance/gas-meter-readings-and-bill-calculation

[gingejbee]

^The simplicity of the meters is not an issue (my gas meter is an easier read than the electricity one). A calculation is needed to convert units recorded into the cost per kWh, but this is explained on paper bills and online accounts.

[Canary42]

The only real answer is suck it and see , put them on for an hour without using any other appliances on the same fuel, and take the meter readings before and after, then compute the cost using the energy supplier's figures. But this won't apply consistently for every other hour because it will be affected by ambient temperature, and room usage.