Can a hot water bottle stay hot all night?

But does it let any heat out if it's very well insulated?

The secret to keeping a hot water bottle hot all night is putting it in a well insulated cover.
My HWB gets filled at 10pm and is still good at 8am next morning.

I saw a similar tip of putting coins in, I assume they work the same as foil in retaining heat.

Yes Welbeck thats sensible. Perhaps not the best idea. Well I have done it now and will see ....but maybe not do it again.

As you say I urge caution.

the instructions form part of the safety provisions of a product.
this is not an intended use of the HWB, and it will not have been tested under those conditions.
this practice may adversely affect the performance or integrity of the HWB.
i urge caution.

Couldn't wait till bed time. I cut 6 strips of foil...which apparently will sharpen my scissors .. and rolled them into balls. Three shiny side inside three shiny aide outside not sure if it makes a difference.

I made sure they didnt obstruct the opening/spout and carefully poured the water in. Its now in bed and I shall test the heat when I go to bed at about 10.00. I should get out more!!!

It can if it’s an old fashioned stone one! I managed to get new rubber washers for my parents ancient ones! Water would be warm enough to use to wash in next morning!

Well now I'm intrigued. I'm going to have to try it!!!

It's worth a try....and if it doesn't work I shall flatten out the balls of foil and re use!!! if I can get them out of course. Can't wait to go to bed.

Costs a lot more money than a hot water bottle and doesn’t stay warm all night

I ve never heard of that but will give it a go tonight helterskelter

Would recommend an electric blanket ….