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Hot Water Bottle Instructions: 13 Golden Rules (2022)

Updated: Jan 21, 2023


Hot water bottle with instructions icon

How should you use your hot water bottle? Is there a specific way to heat it? How about storage?


If you've bought a hot water bottle for the very first time or haven't used one in a while, you may not know or remember how to safely use one.


It's also likely you've thrown your hot water bottle instructions away or misplaced them.




Not to worry: we've listed and described 13 golden rules of safely filling, using, and storing a hot water bottle.


This list has been made based on the official instructions of a Fashy, hot water bottle purchased in December 2022. Fashy is a hot water bottle manufacturer since 1948.



Filling your hot water bottle

Hot water bottle with drop of water icon

1. Steps to fill a hot water bottle

a) Hold your hot water bottle by the neck and gently pour warm water into it, up to two-thirds.


b) Remove the remaining air from the hot water bottle by slowly laying it onto a flat surface - still holding it by the neck. Slowly push the air out using your palm, bend the neck of the hot water bottle and screw the stopper on.


c) Check the hot water bottle is sealed by gently turning it upside down over your sink. If no leaks are apparent and the bottle is not dripping, use a cloth to dry the funnel/mouth of the hot water bottle and it will be ready for use!


2. Fill with hot water that is a maximum of 80 degrees Celsius

It is important you do not fill your hot water bottle with boiling water as this may damage the material. Your hot water bottle won't last as long and will be prone to tears if you use boiling water. Use hot water that is a maximum of 80 degrees Celsius.


3. Fill your hot water bottle up to two-thirds (2/3) maximum

Slowly fill your hot water bottle to a maximum of two-thirds of its full capacity. Filling it to its maximum capacity - all the way to the top - will lead to too much pressure on the inside.


This in turn may lead your hot water bottle to burst. In addition, filling your hot water bottle up to the top may lead to water overflowing, splashing, and burning your hands. Read our full article on how much you should fill a hot water bottle.


4. Avoid using hot tap water to fill your hot water bottle

Water from your home water system may contain impurities which could damage the inside of your hot water bottle. In turn, this may affect its longevity.


Using a hot water bottle safely

Man and woman reading in bed illustration

5. Check your hot water bottle has the British Safety label (BS 1970:2012)

This British Standard (BS 1970:2012) guarantees your hot water bottle respects manufacturing and safety standards for commercialization. In other words, if your hot water bottle respects this standard, it is safe for use.


If this stamp is not mentioned anywhere on your bottle or in the instructions that came with your item, this may be unsafe. Purchase a bottle which presents this label.


6. Check for leaks before using

Double-check your hot water bottle is in good condition before each use. To do this, fill it with cold water, screw the stopper on and gently press on the bottle's body over the sink to see if any water is dripping and if there are any leaks. If you don't see apparent tears or water leaking, you're good to go.


If you suspect a leak or a tear in your bottle, dispose of it and buy a new one. Once you're done with the check, reuse the cold water: heat it and use it for your hot water bottle!


7. Avoid long and direct contact with your skin

Avoid putting your hot water bottle in direct contact with your skin as this may lead to burns. Use a cover or a cloth to wrap around it to prevent direct contact.


Don't apply a hot water bottle on your skin for more than 15 minutes. Stop using the hot water bottle immediately if usage brings discomfort or excessive heat.


8. Use a hot water bottle cover

Using a hot water bottle cover has many benefits. Firstly, it constitutes a layer of protection against the heat of your hot water bottle. It prevents direct contact with your skin and burns.


It also offers a layer of protection in the unlikely event of your hot water bottle leaking or tearing. In addition, a cover will keep your hot water bottle warm longer.


9. Do not heat in a microwave or oven

Rubber and PVC hot water bottles are not to be heated in microwaves or ovens. Only hot water bottles made of food-grade silicone can be heated in microwaves.



10. Do not sit and exercise pressure on your hot water bottle

You should avoid sitting, laying or standing on a hot water bottle as this may lead it to burst, especially if it is overfilled. It cannot be used as a cushion to sit on or as a pillow to sleep on.


Hot water bottles are to be used placed on top of your lap, belly, chest, neck or legs.


11. Do not use for children less than 36 months

Hot water bottles should not be used for children less than 36 months (3 years of age). As a rule, keep hot water bottles away from children without supervision and use a cover at all times to prevent burns on their sensitive skin.


The surface temperature of hot water bottles for children should be below 42 degrees Celsius.


Storing hot water bottles

Hot water bottle storing illustration

12. Remove the stopper/cap when not using your hot water bottle

Remove the stopper when you are not using or planning to store your hot water bottle for a longer period. This will enable air to flow in and out of the hot water bottle and prevent it from rotting or fungus to build up inside.


13. Store your hot water bottle in a dark and dry place

Your hot water bottle should be stored in a dark and dry place. The place of storage should ideally have a temperature between 10 and 25 degrees Celsius. This means room temperature is perfectly acceptable to store a hot water bottle.


Optimal places for storage include a dry drawer or a closet, where you would ideally hang your hot water bottle upside down without its cap to enable airflow.


Make sure the place where your hot water bottle is stored is free of sunlight, grease, oil and extreme temperatures (e.g.: do not store it outdoors, near a radiator, hanging in a shower, or in a cellar).

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