To find out, back in November 2021 we bought the UK's bestselling hot water bottles from Superdrug, Argos, Wilko and more, ranging in price from £6 up to £30, and put them to the test. Hot water bottles have been flying off the shelves as the cost of heating soars but our best hot water bottle pick has just come back into stock
Read on to find out if we think it's worth spending extra money on a pricier hot water bottle.
We filled all of the hot water bottles we tested (including a trendy long hot water bottle) up to two-thirds of their capacity with hot water and tracked how quickly they cooled down over several hours with the covers on and with the covers off.
We also noted how comfortable and easy it was to fill all of the hot water bottles we tested.
Prices and availability last updated 15 February 2023.
What our tests found
So is it worth spending extra money on a more expensive hot water bottle? In short - no, it isn't.
As we recorded the temperature drops over several hours, we found that all of the hot water bottles were within 2°C of each other on average when we ran our tests with the covers off.
If you held a hot water bottle in each hand and one was 2°C hotter than the other, we're not sure you'd be able to say which one was warmer.
Not all of the hot water bottles we tested came with covers, but we repeated the tests with the covers on for those that did to see if it led to much bigger differences. It didn't.
After three hours all of the hot water bottles we tested, with covers on and without, dropped to around body temperature (37°C) or less.
So our advice would be to buy yourself a cheap hot water bottle and put the additional cash towards a thick, high quality cover for it.
That way you're spending less on the part that doesn't make much of a difference (the bottle), and more on the bit where comfort, insulation and appearance come into it (the cover).
Our tests didn't just focus on how warm the hot water bottles stayed, though. We also judged them on comfort, how easy they are to fill and how straightforward they are to look after. See our findings below.
Best hot water bottles
Editor's Choice: Superdrug Hot Water Bottle 1.7L
Capacity: Cover included?: Our verdict:This natural rubber hot water bottle from Superdrug doesn't come with a cover, so it's only as comfy as you make it. But we couldn't find anything wrong with it in our tests and it's available at a great price.
There are two colours available, but there's no option to choose when you order from Superdrug online. You'll find out which colour you've got when it gets delivered. You also get one hot water bottle per purchase, not two, despite the product pictures showing two bottles.
The cup around the lid is wide, making the bottle extra easy to fill and reducing the chances of any stray hot water landing on you or the floor.
We had no trouble pushing the excess air out before sealing it and couldn't spot any rough edges, smells or weaknesses.
Overall it's a simple, cheap hot water bottle that does the job you need with no unwelcome surprises. Go grab yourself one of these and buy a cover for it that suits your tastes.
Choose well, buy better and save money using our expert tips
Cassandra Hot Water Bottle HW0101
Capacity: Cover included?: Our verdict:Although similar in appearance, size and price to the Superdrug hot water bottle, we were put off recommending this Cassandra hot water bottle as it was greasy to touch. It's made from natural rubber as with several other hot water bottles we tested, but this was the only one that felt slimy and unpleasant in our hands.
As with the Superdrug hot water bottle, you get one hot water bottle per purchase and it can be one of the three colours pictured above. There's no option to pick and choose the colour you want.
Besides that we had no problems with it. We found it easy to fill and despite the greasiness we didn't find any odd smells or stains left over from manufacturing.
George Home Grey Teddy Hot Water Bottle
Capacity: Cover included?: Our verdict:We had no trouble filling up this cheap hot water bottle, and we'd be happy to recommend it if it wasn't for its unpleasant, rubbery smell and underwhelming cover.
At £6 you won't expect to get the world's softest cover, but this one felt cheap and matted to our testers.
The cover is also hand wash-only, and it's recommended that you put it through a short spin cycle after washing to help it dry.
Wilko Hot Water Bottle with Cover
Capacity: Cover included?: Our verdict:We found it easy to fill and didn't notice any odd smells or stains, but we thought the cover was thin and not overly comfortable. It's also hand wash-only, so it's not the easiest hot water bottle to look after.
These natural rubber hot water bottles come in a variety of colours, but when buying online there's no option to choose which colour you'd like, so you get what you're given.
Although there are three options shown above, you'll get one hot water bottle per purchase.
Cassandra Long Cable Knit Hot Water Bottle
Capacity: Cover included?: Our verdict:It may look snuggly, but we thought Cassandra's Long Cable Knit Hot Water Bottle wasn't especially comfortable, and we found it very difficult to fill.
Although the cover was soft to touch, we thought the sides of the bottle were tough and hard, making it less comfortable to hug, and the bottle also had an unpleasant, rubbery smell. The cover is also hand wash-only, so you won't be able to bung it in the washing machine when it needs cleaning.
Because of its length, the water you pour in congregates at the bottom. You can't let go of the top as it risks flopping over, so to squeeze out the remaining air we had to hug it and squeeze it with our legs at the same time.
The Body Hot Water Bottle By YUYU
Capacity: Cover included?: Our verdict:As was the case with Cassandra's long hot water bottle, we found this one difficult to fill due to its shape, and it's less comfortable than it appears.
The cover is however very soft to touch, and there's a strap you can loop together so you can wear the hot water bottle around your waist or shoulders. We would question the usefulness of this, though, as although you'll be wrapped up, you won't be able to sit back or lie down as you'll put your body weight on the hot water bottle.
The YUYU hot water bottle was another that we found had an unpleasant smell left over from manufacturing, and when we pulled the hot water bottle out of the cover we also saw the bottle was stained.
The cover can however be washed at 30°C in the washing machine, so it is at least easy to keep it clean.
Samply Transparents 1.8L Hot Water Bottle
Capacity: Cover included?: Our verdict:Both the cover and the bottle inside smelled like chemicals when we took them out of their packaging.
The cup at the top of the hot water bottle is large, but it pinches inwards in the middle, making the opening smaller for pouring in your water.
We think the cover is soft, but no instructions are given as to how to care for or clean it so you'll have to take your best guess and hope it doesn't get ruined.
The Hot Water Bottle Shop 2 Litre Eco Hot Water Bottle with Orange Zip Cover (rubberless)
Capacity: Cover included?: Our verdict:The Hot Water Bottle Shop says this bottle is made of recyclable plastic that is 90% 'biobased', 9% 'fossil carbon', and PVC and phthalate-free. You can recycle it with your household plastic recycling, so it's easy to dispose of it responsibly.
Sadly we found the plastic bottle tough and hard, and the thin cover did little to soften it. The opening at the top of the bottle is wide so it's easy to pour water in, but there's no cup to catch any wayward water so there's a higher chance of you burning yourself if you miss.
This also means that when squeezing out the excess air the water comes very close to coming out of the top, so there's very little room for error when filling this bottle up.
The cover is machine-washable at 40°C, so if it gets stained or dirty it's a low-effort job to get it clean again.
Long hot water bottles: are they a fad?
A long hot water bottle sounds like a great idea - who wouldn't want to be cosy and warm from head to toe?
But the two long hot water bottles we tested left us thinking more about the cons than the pros.
They're difficult to fill
How to care for and clean your hot water bottle
Don't use boiling waterDon't fill them more than two thirds of their capacity Empty and dry them after each useAvoid abrasive cleaning chemicalsundefinedsource https://www.which.co.uk/news/article/does-paying-more-get-you-a-better-hot-water-bottle-aSDV19k5ZLDi